OvmfPkg: use HII type PCDs for TPM2 config related variables

OvmfPkg: use HII type PCDs for TPM2 config related variables

The HII pages that are part of Tcg2ConfigDxe expect the following PCDs
to be of dynamic HII type, so declare them as such.

  gEfiSecurityPkgTokenSpaceGuid.PcdTcgPhysicalPresenceInterfaceVer
  gEfiSecurityPkgTokenSpaceGuid.PcdTpm2AcpiTableRev

Currently, the TPM2 ACPI table is not produced, since we do not
incorporate the Tcg2Smm module, which implements the SMI based
physical presence interface exposed to the OS.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>