msm: 8930: Configure SDC2 slot for SDIO

SDC2 slot is designed for use with SDIO devices and so configure
the SDC2 slot for that purpose. But its not enabled by default since
the gpios are shared with ethernet, usb.

Change-Id: I8a4c5b7a76e902bfbd603a0d7b952f672bea7a00
Signed-off-by: Krishna Konda <kkonda@codeaurora.org>