mmc: omap_hsmmc: switch default/idle pinctrl states in runtime hooks

These are predefined states of the driver model. When not present,
as if not set in the device tree, they become no-ops.
Explicitly selecting the default state is not needed since the
device core layer sets pin mux to "default" state before probe.
This is not the simplest implementation, on AM335x at least, we could
switch to idle at any point in the suspend hook, only the default state
needs to be set before writing to the irq registers or an IRQ might get
lost.

Acked-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Andreas Fenkart <afenkart@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>