mmc: host: sdhci-msm: Toggle FIFO write clk after MCLK ungated

During GCC level clock gating of MCLK, the async FIFO
gets into some hang condition, such that for the next
transfer after MCLK ungating, first bit of CMD response
doesn't get written in to the FIFO. This cause the CPSM
to hang eventually leading to SW timeout.

To fix the issue, toggle the FIFO write clock after
MCLK ungated to get the FIFO pointers and flags to
valid states.

Change-Id: I29faefbcb814fcc36fb8afcf7ec2cb51c553b5e6
Signed-off-by: Ram Prakash Gupta <rampraka@codeaurora.org>