MdePkg/Btt.h: Add Block Translation Table definitions

BTT definitions are defined in UEFI spec 2.7, to defines
a layout and set of rules for doing block I/O that provide
powerfail write atomicity of a single block in NVDIMM.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

MdePkg/MdePkg.dec

@@ -645,6 +645,12 @@
   gEfiHiiImageDecoderNameJpegGuid           = { 0xefefd093, 0x0d9b, 0x46eb, { 0xa8, 0x56, 0x48, 0x35, 0x07, 0x00, 0xc9, 0x08 }}
   gEfiHiiImageDecoderNamePngGuid            = { 0xaf060190, 0x5e3a, 0x4025, { 0xaf, 0xbd, 0xe1, 0xf9, 0x05, 0xbf, 0xaa, 0x4c }}
 
+  #
+  # GUIDs defined in UEFI2.7
+  #
+  ## Include/Guid/Btt.h
+  gEfiBttAbstractionGuid         = { 0x18633bfc, 0x1735, 0x4217, { 0x8a, 0xc9, 0x17, 0x23, 0x92, 0x82, 0xd3, 0xf8 }}
+
   #
   # GUID defined in PI1.0
   #