OvmfPkg: Realize EfiMemoryAcceptProtocol in AmdSevDxe

OvmfPkg: Realize EfiMemoryAcceptProtocol in AmdSevDxe

When a guest OS does not support unaccepted memory, the unaccepted
memory must be accepted before returning a memory map to the caller.

EfiMemoryAcceptProtocol is defined in MdePkg and is implemented /
Installed in AmdSevDxe for AMD SEV-SNP memory acceptance.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
Message-Id: <20221108164616.3251967-2-dionnaglaze@google.com>