OvmfPkg: build PiSmmCpuDxeSmm for -D SMM_REQUIRE

OvmfPkg: build PiSmmCpuDxeSmm for -D SMM_REQUIRE

At this point we can enable building PiSmmCpuDxeSmm.

CPU specific features, like SMRR detection, and functions that are used to
initialize SMM and process SMIs, are abstracted through the
SmmCpuFeaturesLib class for the PiSmmCpuDxeSmm module. Resolve it to our
own implementation under OvmfPkg -- it allows PiSmmCpuDxeSmm to work with
QEMU's and KVM's 64-bit state save map format, which follows the
definition from AMD's programmer manual.

SmmCpuPlatformHookLib provides platform specific functions that are used
to initialize SMM and process SMIs. Resolve it to the one Null instance
provided by UefiCpuPkg, which is expected to work for most platforms.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
[pbonzini@redhat.com: resolve the SmmCpuFeaturesLib class to OVMF's own
 instance]

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19061 6f19259b-4bc3-4df7-8a09-765794883524