mmc: Kconfig: Change MMC_SDHCI_MSM to be static module

Change the CONFIG_MMC_SDHCI_MSM from loadable kernel module
to a statically linked module.

Change-Id: Ic6d40caf8fa61235dd63bb39be5742b1dc0079bc
Signed-off-by: Bao D. Nguyen <nguyenb@codeaurora.org>