mmc: sdhci-of-esdhc: Fixup compile error

The commit below introduced compile errors, let's fix them.
mmc: sdhci-of-esdhc: remove platform_suspend/platform_resume callbacks

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>