ODROID-C: mmc: Initate MMC power state on reboot

To support MMC's reset from UHS-I mode, power must be back to 3.3V for its bus
and MMC Card's power must be done by power reset. Otherwise MMC card won't be
back from UHS mode and can not be initiated on next warm boot.

Change-Id: Ie1cb6bdafd791a10c7acbf389c02e24d6719c9c8
Signed-off-by: Dongjin Kim <tobetter@gmail.com>