When an mmc card has the MMC_PM_KEEP_POWER flag, it shouldn't
be powered off on suspend (and thus doesn't have to be powered-on
on resume)

While on it, change the suspend flow a bit, to make it a bit
easier to follow.
Signed-off-by: NEliad Peller <eliad@wizery.com>
Acked-by: NChris Ball <cjb@laptop.org>
Signed-off-by: NTony Lindgren <tony@atomide.com>