OvmfPkg: Create SP800155 HOBs from QemuFwCfgFile

Signed firmware measurements are allowed to be passed along to in the
TCG and CC event logs according to the TCG PC Client Platform Firware
Profile. The event logs include events that Tcg2Dxe reads from
appropriately GUIDed HOBs, so allow opt/org.tianocode/sp800155evts to
pass along events that the VMM sees fit to provide.

The VMM may provide reference measurements through UEFI variables that
it references from the SP800-155 event3 structure given the appropriate
RIM locator type, or via URL, etc.

After the events are read from fw_cfg, they are written one-by-one to
EFI_HOB_GUID_TYPE HOBs created for the events. The name they target
gTcg800155PlatformIdEventHobGuid for the later Dxe driver to use to
extend the event log.

The internal consistency of the event, i.e., the fact that the sum total
of sizes present in the event are within the range of the
opt/org.tianocode/sp800155evts file size, is checked in order to proceed
to the next event in the file that immediately follows.

Signed-off-by: Dionna Glaze <dionnaglaze@google.com>

OvmfPkg/PlatformPei/Platform.c

@@ -40,6 +40,7 @@
 #include <OvmfPlatforms.h>
 
 #include "Platform.h"
+#include "PlatformId.h"
 
 EFI_PEI_PPI_DESCRIPTOR  mPpiBootMode[] = {
   {
@@ -363,6 +364,7 @@ InitializePlatform (
     MiscInitializationForMicrovm (PlatformInfoHob);
   } else {
     MiscInitialization (PlatformInfoHob);
+    PlatformIdInitialization (PeiServices);
   }
 
   IntelTdxInitialize ();