mmc: block: Add check to mmc_blk_part_switch

Sometimes after failing RPMB access due to card in bad voltgae state,
If issue USER parition access request,it fails as card is already in
bad state. Fix this by adding error handling to mmc_blk_part_switch()
and by resetting the block whenever partition switch fails.

Change-Id: I245683b0b0a06b13938036dbc37e87ed1ef70b89
Signed-off-by: Pavan Anamula <pavana@codeaurora.org>
[xiaonian@codeaurora.org: fixed trivial merge conflicts]
Signed-off-by: Xiaonian Wang <xiaonian@codeaurora.org>