gpio/omap: use flag to identify wakeup domain

In omap3, save/restore context is implemented for GPIO banks 2-6 as GPIO bank1
is in wakeup domain. Instead of identifying bank's power domain by bank id,
use 'loses_context' flag which is filled by pwrdm_can_ever_lose_context()
during dev_init.

For getting the powerdomain pointer, omap_hwmod_get_pwrdm() is used.
omap_device_get_pwrdm() could not be used as the pwrdm information needs to be
filled in pdata, whereas omap_device_get_pwrdm() could be used only after
omap_device_build() call.

Signed-off-by: Charulatha V <charu@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/plat-omap/include/plat/gpio.h b/arch/arm/plat-omap/include/plat/gpio.h
index acf1c77..6eb035c 100644
--- a/arch/arm/plat-omap/include/plat/gpio.h
+++ b/arch/arm/plat-omap/include/plat/gpio.h
@@ -198,6 +198,7 @@
 	int bank_width;		/* GPIO bank width */
 	int bank_stride;	/* Only needed for omap1 MPUIO */
 	bool dbck_flag;		/* dbck required or not - True for OMAP3&4 */
+	bool loses_context;	/* whether the bank would ever lose context */
 
 	struct omap_gpio_reg_offs *regs;
 };