OvmfPkg/SmbiosPlatformDxe: create Xen-specific module INF file

OvmfPkg/SmbiosPlatformDxe: create Xen-specific module INF file

"OvmfPkg/SmbiosPlatformDxe" is structured somewhat differently from the
drivers duplicated and trimmed thus far in this series. The final QEMU and
Xen versions will share a relatively significant amount of code, therefore
duplicating the whole driver is less useful, even temporarily. Instead,
duplicate the INF file, in preparation for customizing the entry point
function.

Because ArmVirtXen doesn't actually include OvmfPkg/SmbiosPlatformDxe [*],
there is only one platform that's supposed to consume the new driver:
OvmfXen. Switch OvmfXen to the new driver at once.

[*] See commit 164cf4038357 ("OvmfPkg: SmbiosPlatformDxe: restrict current
    Xen code to IA32/X64", 2015-07-26).

This patch is best viewed with "git show --find-copies-harder".

Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Julien Grall <julien@xen.org>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2122
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20210526201446.12554-42-lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>