mmc: msm_sdcc: fixup for enabling MMC_CLKGATE feature for SDIO cards

In the current implementation, turning off SDCC clocks when
SDIO card is inserted, is controlled by the SDCC driver in
suspend/resume callbacks. This makes the dynamic clock gating
(MMC_CLKGATE) feature, when enabled, to be broken for SDIO cards,
as configuring of sdio wakeup interrupt is entirely handled
in system suspend/resume callbacks. Handle this by moving all
of the wakeup handling code to generic set_ios function which can be
called either from core layer or driver layer.

Since the SDCC controller supports asynchronous notification of
SDIO card activity when the clocks are off use this for enabling
MMC_CLKGATE feature which helps in TCX0 during idle state.

Also, handle the case where the SDIO function driver is not interested
in waking up the system during suspend but the SDCC driver still
configures DAT1 line as wakeup interrupt.

Change-Id: I260ae2161cfe9160f93e6af4f9b6c34db96397c0
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>