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>
msm: msm_sdcc: Add DT support for SDIO wakeup interrupt

Add device tree support for system wakeup on SDCC DAT1 line
assertion (LOW) by SDIO cards while system is suspended.

If SDC slot has dedicated MSM pins, board DT should specifiy MPM
interrupt line mapping (using new "qcom,dat1-mpm-int" property)
else a gpio to irq mapping of the corresponding DAT1 line should
be specified.

Change-Id: I7d1b02a4d35a1af12978be2aabd47ab99cb7956c
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>

Conflicts:
	Documentation/devicetree/bindings/mmc/msm_sdcc.txt
mmc: removed useless merging code.
mmc: cleaning code.