QcomModulePkg: Add DDR size check for choosing DTB and DTBO

DDR size check is needed for choosing DTB and DTBO, if a target
has more than one DDR variant like Bengal. Bits 8-10 of subtype
in qcom,board-id is used for storing DDR information in DT.

Change-Id: Ib62c53336e30ed448db368fbc39e849134d9d267
4 files changed