ARM: OMAP5+: GPIO: Add GPIO_TO_PIN() macro

GPIO_TO_PIN(bank, bank_gpio) returns the GPIO index
from the GPIO bank number and bank's GPIO offset number.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>

arch/arm/include/asm/arch-omap5/gpio.h

@@ -34,4 +34,8 @@
 #define OMAP54XX_GPIO7_BASE		0x48051000
 #define OMAP54XX_GPIO8_BASE		0x48053000
 
+
+/* Get the GPIO index from the given bank number and bank gpio */
+#define GPIO_TO_PIN(bank, bank_gpio)	(32 * (bank - 1) + (bank_gpio))
+
 #endif /* _GPIO_OMAP5_H */