ARM: 7622/1: mmc: mmci: Gate the clock in runtime suspend to save power

The amba bus is already performing same actions but for the apb_pclk.
So here we just make sure the clock to card is gated as well to save
more power. At runtime resume we will thus restore the clock again.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Liu <kliu5@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>