mmc: mxc: Use the new PM macros

Use DEFINE_SIMPLE_DEV_PM_OPS() instead of the SIMPLE_DEV_PM_OPS()
macro, along with using pm_sleep_ptr() as this driver doesn't handle
runtime PM.

This makes it possible to remove the #ifdef CONFIG_PM guard around
the suspend/resume functions.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>