mmc: sdhci-spear: Don't call clk_{un}prepare() in suspend/resume

clk_{un}prepare is mandatory for platforms using common clock
framework. Because for SPEAr we don't do anything in clk_{un}prepare()
calls, just call them once in probe/remove.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>