mmc: msm_sdcc: fix mismatched clock api calls

During probe after setting up sdcc core clock with clk_enable_prepare(),
if there are any errors, the core clock is turned off but with
clk_disable() instead of the matching clk_disable_unprepare(). This
causes the clock driver to retain the vote for core clock thus
preventing tcxo shutdown.

Change-Id: I818a7c70800d23804d06dd768159c4de6ef5eda1
Signed-off-by: Krishna Konda <kkonda@codeaurora.org>