mmc: sdhci: Do not use spin lock in set_ios paths

The spin lock is not necessary in set_ios. Anything that is racing with
changes to the I/O state is already broken. The mmc core already provides
synchronization via "claiming" the host. So remove spin_lock and friends
from sdhci_set_ios and related callbacks.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>