MdePkg/Include/IndustryStandard: Remove VS20xx workaround

Remove workaround for the redefinition of the type
RUNTIME_FUNCTION that is generated when building with
VS20xx tool chains and using windows include files.
The correct location for this fix is in the EmulatorPkg
in the WinInclude.h file that addresses all the name
collisions between edk2 types and windows types.

The commit that added the workaround is:

ff52068d92

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rebecca Cran <rebecca@bsdio.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
Reviewed-by: Rebecca Cran <rebecca@bsdio.com>

MdePkg/Include/IndustryStandard/PeImage.h

@@ -678,9 +678,6 @@ typedef struct {
   //
 } EFI_IMAGE_DEBUG_CODEVIEW_MTOC_ENTRY;
 
-// avoid conflict with windows header files
-#ifndef RUNTIME_FUNCTION_INDIRECT
-
 //
 // .pdata entries for X64
 //
@@ -690,8 +687,6 @@ typedef struct {
   UINT32    UnwindInfoAddress;
 } RUNTIME_FUNCTION;
 
-#endif
-
 typedef struct {
   UINT8    Version             : 3;
   UINT8    Flags               : 5;