gpio/omap: conslidate enable/disable of GPIO IRQs, remove ifdefs

Cleanup GPIO IRQ enable/disable handling by removing SoC-specific

Also split enable/disable IRQ into separate functions for better
readability and also facilitate potentially moving to generic irq_chip
in the future.

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 aedd732..c7e3a56 100644
--- a/arch/arm/plat-omap/include/plat/gpio.h
+++ b/arch/arm/plat-omap/include/plat/gpio.h
@@ -182,6 +182,11 @@
 	u16 clr_dataout;
 	u16 irqstatus;
 	u16 irqstatus2;
+	u16 irqenable;
+	u16 set_irqenable;
+	u16 clr_irqenable;
+
+	bool irqenable_inv;
 };
 
 struct omap_gpio_platform_data {