UPSTREAM: mmc: sdhci-msm: fix mutex while in spinlock

mutexes can sleep and therefore should not be taken while holding a
spinlock. move clk_get_rate (can sleep) outside the spinlock protected
region.

BUG=b:136220108
TEST=Tested on SoC QCS404

(cherry picked from commit 5e6b6651
https://github.com/torvalds/linux.git

)

Change-Id: Ia185975b4fdabc9ae341e9f23d5cb68f8f937966
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Vamsi Singamsetty <vamssi@codeaurora.org>