Creates LRDIMM mrep/dwl calibration recorder class

Change-Id: I733b136b65c1cf6a8e54f7ffa85fe864cf9050ef
Original-Change-Id: Ic3f1c1d3ee4e19a3c6b33b3472e4a513985321a5
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/69489
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Tested-by: HWSV CI <hwsv-ci+hostboot@us.ibm.com>
Reviewed-by: STEPHEN GLANCY <sglancy@us.ibm.com>
Reviewed-by: Louis Stermole <stermole@us.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>

src/import/generic/memory/lib/utils/shared/mss_generic_consts.H

@@ -244,6 +244,17 @@ enum guard_band : uint16_t
 
 }// spd
 
+///
+/// @brief DIMM nibble mask
+/// @note nibble0: 4 high bits, nibble1: 4 low bits
+///
+enum nibble_mask
+{
+    MASK_NIBBLE0 = 0xf0,
+    MASK_NIBBLE1 = 0x0f,
+};
+
+
 }// mss
 
 #endif