OvmfPkg: Update PlatformPei to support Tdx guest

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

OvmfPkg/PlatformPei is updated to support Tdx guest. There are below
major changes.
 - Set Tdx related PCDs
 - Publish Tdx RamRegions

In this patch there is another new function BuildPlatformInfoHob ().
This function builds EFI_HOB_PLATFORM_INFO which contains the
HostBridgeDevId. The hob is built in both Td guest and Non-Td guest.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>

OvmfPkg/PlatformPei/Platform.c

@@ -310,6 +310,17 @@ MaxCpuCountInitialization (
   ASSERT_RETURN_ERROR (PcdStatus);
 }
 
+/**
+ * @brief Builds PlatformInfo Hob
+ */
+VOID
+BuildPlatformInfoHob (
+  VOID
+  )
+{
+  BuildGuidDataHob (&gUefiOvmfPkgPlatformInfoGuid, &mPlatformInfoHob, sizeof (EFI_HOB_PLATFORM_INFO));
+}
+
 /**
   Perform Platform PEI initialization.
 
@@ -386,7 +397,9 @@ InitializePlatform (
     MiscInitialization (&mPlatformInfoHob);
   }
 
+  IntelTdxInitialize ();
   InstallFeatureControlCallback ();
+  BuildPlatformInfoHob ();
 
   return EFI_SUCCESS;
 }