OvmfPkg/OvmfPkg.dec: Add PCD definitions used by copied CSM modules

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1811

This commit will add the PCD definitions consumed by the duplicated
drivers:

* VideoDxe
* LegacyBiosDxe

into the OvmfPkg DEC file.

Please note that, instead of adding these PCDs under section:
[PcdsFixedAtBuild, PcdsDynamic, PcdsDynamicEx, PcdsPatchableInModule]

as in IntelFrameworkModulePkg.dec file, they are added in section:
[PcdsFixedAtBuild]

in OvmfPkg.dec instead.

Cc: Ray Ni <ray.ni@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Hao A Wu <hao.a.wu@intel.com>
Reviewed-by: David Woodhouse <dwmw2@infradead.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

OvmfPkg/OvmfPkg.dec

@@ -160,6 +160,64 @@
   #  For the corresponding bits, 0 = Edge triggered and 1 = Level triggered.
   gUefiOvmfPkgTokenSpaceGuid.Pcd8259LegacyModeEdgeLevel|0x0000|UINT16|0x5
 
+  ## Indicates if BiosVideo driver will switch to 80x25 Text VGA Mode when
+  #  exiting boot service.
+  #   TRUE  - Switch to Text VGA Mode.
+  #   FALSE - Does not switch to Text VGA Mode.
+  gUefiOvmfPkgTokenSpaceGuid.PcdBiosVideoSetTextVgaModeEnable|FALSE|BOOLEAN|0x28
+
+  ## Indicates if BiosVideo driver will check for VESA BIOS Extension service
+  #  support.
+  #   TRUE  - Check for VESA BIOS Extension service.
+  #   FALSE - Does not check for VESA BIOS Extension service.
+  gUefiOvmfPkgTokenSpaceGuid.PcdBiosVideoCheckVbeEnable|TRUE|BOOLEAN|0x29
+
+  ## Indicates if BiosVideo driver will check for VGA service support.
+  #  NOTE: If both PcdBiosVideoCheckVbeEnable and PcdBiosVideoCheckVgaEnable
+  #  are set to FALSE, that means Graphics Output protocol will not be
+  #  installed, the VGA miniport protocol will be installed instead.
+  #   TRUE  - Check for VGA service.<BR>
+  #   FALSE - Does not check for VGA service.<BR>
+  gUefiOvmfPkgTokenSpaceGuid.PcdBiosVideoCheckVgaEnable|TRUE|BOOLEAN|0x2a
+
+  ## Indicates if memory space for legacy region will be set as cacheable.
+  #   TRUE  - Set cachebility for legacy region.
+  #   FALSE - Does not set cachebility for legacy region.
+  gUefiOvmfPkgTokenSpaceGuid.PcdLegacyBiosCacheLegacyRegion|TRUE|BOOLEAN|0x2b
+
+  ## Specify memory size with bytes to reserve EBDA below 640K for OPROM.
+  #  The value should be a multiple of 4KB.
+  gUefiOvmfPkgTokenSpaceGuid.PcdEbdaReservedMemorySize|0x8000|UINT32|0x2c
+
+  ## Specify memory base address for OPROM to find free memory.
+  #  Some OPROMs do not use EBDA or PMM to allocate memory for its usage,
+  #  instead they find the memory filled with zero from 0x20000.
+  #  The value should be a multiple of 4KB.
+  #  The range should be below the EBDA reserved range from
+  #  (CONVENTIONAL_MEMORY_TOP - Reserved EBDA Memory Size) to
+  #  CONVENTIONAL_MEMORY_TOP.
+  gUefiOvmfPkgTokenSpaceGuid.PcdOpromReservedMemoryBase|0x60000|UINT32|0x2d
+
+  ## Specify memory size with bytes for OPROM to find free memory.
+  #  The value should be a multiple of 4KB. And the range should be below the
+  #  EBDA reserved range from
+  #  (CONVENTIONAL_MEMORY_TOP - Reserved EBDA Memory Size) to
+  #  CONVENTIONAL_MEMORY_TOP.
+  gUefiOvmfPkgTokenSpaceGuid.PcdOpromReservedMemorySize|0x28000|UINT32|0x2e
+
+  ## Specify the end of address below 1MB for the OPROM.
+  #  The last shadowed OpROM should not exceed this address.
+  gUefiOvmfPkgTokenSpaceGuid.PcdEndOpromShadowAddress|0xdffff|UINT32|0x2f
+
+  ## Specify the low PMM (Post Memory Manager) size with bytes below 1MB.
+  #  The value should be a multiple of 4KB.
+  # @Prompt Low PMM (Post Memory Manager) Size
+  gUefiOvmfPkgTokenSpaceGuid.PcdLowPmmMemorySize|0x10000|UINT32|0x30
+
+  ## Specify the high PMM (Post Memory Manager) size with bytes above 1MB.
+  #  The value should be a multiple of 4KB.
+  gUefiOvmfPkgTokenSpaceGuid.PcdHighPmmMemorySize|0x400000|UINT32|0x31
+
 [PcdsDynamic, PcdsDynamicEx]
   gUefiOvmfPkgTokenSpaceGuid.PcdEmuVariableEvent|0|UINT64|2
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashVariablesEnable|FALSE|BOOLEAN|0x10