OvmfPkg: include NvmExpressDxe driver

OvmfPkg: include NvmExpressDxe driver

QEMU emulates NVMe. NvmExpressDxe seems to work well with it. The relevant
QEMU options are

  -drive id=drive0,if=none,format=FORMAT,file=PATHNAME \
  -device nvme,drive=drive0,serial=SERIAL

where the required SERIAL value sets the Serial Number (SN) field of the
"Identify Controller Data Structure". It is an ASCII string with up to 20
characters, which QEMU pads with spaces to maximum length.

(Refer to "NVME_ADMIN_CONTROLLER_DATA.Sn" in
"MdeModulePkg/Bus/Pci/NvmExpressDxe/NvmExpressHci.h".)

Cc: Vladislav Vovchenko <vladislav.vovchenko@sk.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Reference: https://github.com/tianocore/edk2/issues/48
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Tested-by: Vladislav Vovchenko <vladislav.vovchenko@sk.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19791 6f19259b-4bc3-4df7-8a09-765794883524