mmc: block: support RPMB with CMDQ framework

CMDQ is not supported for RPMB partition. Hence, for RPMB requests
the controller is kept in HALT state and then CMDQ is disabled in
the card.

Change-Id: I1242841d5fa063b542e35dcff95694ef5e88737a
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>