OvmfPkg: Move XenRealTimeClockLib from ArmVirtPkg

Move XenRealTimeClockLib from ArmVirtPkg to OvmfPkg so it can be used
from the OvmfPkg by the following patch, "OvmfPkg/OvmfXen: use
RealTimeClockRuntimeDxe from EmbeddedPkg"

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-35-anthony.perard@citrix.com>

ArmVirtPkg/ArmVirtXen.dsc

@@ -27,7 +27,7 @@
 
 [LibraryClasses]
   SerialPortLib|OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.inf
-  RealTimeClockLib|ArmVirtPkg/Library/XenRealTimeClockLib/XenRealTimeClockLib.inf
+  RealTimeClockLib|OvmfPkg/Library/XenRealTimeClockLib/XenRealTimeClockLib.inf
   XenHypercallLib|OvmfPkg/Library/XenHypercallLib/XenHypercallLib.inf
 
   ArmGenericTimerCounterLib|ArmVirtPkg/Library/XenArmGenericTimerVirtCounterLib/XenArmGenericTimerVirtCounterLib.inf

Maintainers.txt

@@ -114,7 +114,6 @@ R: Leif Lindholm <leif.lindholm@linaro.org>
 ArmVirtPkg: modules used on Xen
 F: ArmVirtPkg/ArmVirtXen.*
 F: ArmVirtPkg/Library/XenArmGenericTimerVirtCounterLib/
-F: ArmVirtPkg/Library/XenRealTimeClockLib/
 F: ArmVirtPkg/Library/XenVirtMemInfoLib/
 F: ArmVirtPkg/PrePi/
 F: ArmVirtPkg/XenAcpiPlatformDxe/
@@ -374,6 +373,7 @@ F: OvmfPkg/Library/XenConsoleSerialPortLib/
 F: OvmfPkg/Library/XenHypercallLib/
 F: OvmfPkg/Library/XenIoMmioLib/
 F: OvmfPkg/Library/XenPlatformLib/
+F: OvmfPkg/Library/XenRealTimeClockLib/
 F: OvmfPkg/OvmfXen.*
 F: OvmfPkg/OvmfXenElfHeaderGenerator.c
 F: OvmfPkg/PlatformPei/MemDetect.c