mmc: msm_sdcc: fix SD card detect gpio configuration

SDCC driver is calling the gpio_request() everytime card detect
interrupt fires and releases the gpio (gpio_free()) after reading
the GPIO status. Instead this patch calls gpio_request() for card detect
GPIO once during probe instead of doing it everytime before reading
the current status of GPIO. GPIO is released during platform suspend
and acquired again during platform resume.

Change-Id: If87e343657fbfbc7b7ebdfad03c547ad170a1c28
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>