ARM: 7832/1: mmc: mmci: Use optional sleep pinctrl state

By optionally putting the pins into sleep state in the .runtime_suspend
callback we can accomplish two things. One is to minimize current leakage
from pins and thus save power, second we can prevent the IP from driving
pins output in an uncontrolled manner, which may happen if the power domain
drops the domain regulator.

When returning from idle, entering .runtime_resume callback, the pins
are restored to default state.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rickard Andersson <rickard.andersson@stericsson.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>