Add p9a version of eff_memory_size API

  Adds mc_type template on eff_memory_size functions to avoid
  symbol duplication on future systems.

Change-Id: I9de70c3713a680341aa413316119132be7a21fc0
Original-Change-Id: I11552c94ac1dfc7ea367e0a6bb5d63e13d18c183
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/72790
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: Mark Pizzutillo <mark.pizzutillo@ibm.com>
Reviewed-by: STEPHEN GLANCY <sglancy@us.ibm.com>
Tested-by: HWSV CI <hwsv-ci+hostboot@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>

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

@@ -377,6 +377,7 @@ struct procTraits<proc_type::AXONE>
     enum
     {
         EXP_PORTS_PER_OCMB = 1,
+        DIMMS_PER_PORT = 2,
     };
 };