mmc: sdhci-msm: set core in proper mode before reset

During probe disable the HC mode since the reset is done in
SDCC mode. HC mode will get set after the reset is complete
before the rest of the initialization is done.

Change-Id: I1fdc633c218447c15c8caad24e2805e7510088f2
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>