mmc: card: Update multi_cmd_ioctl path to support cmdq

Halt cmdq in multi_cmd_ioctl path before processing IOCTL
commands and un-halt it once it has done with IOCTL processing.

Without this change, the mmc driver would try to process legacy
commands when host & card are in cmdq mode which may result
in unexpected interrupt / illegal command errors.

Change-Id: I254a1a752f770ffd03331c4856aa9f54867092dc
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>