davinci: Macro to convert GPIO signal to GPIO pin number

Adds a macro to convert the GPIO signal passed as bank number
and signal to GPIO pin number.
Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-davinci/include/mach/gpio.h

@@ -42,6 +42,9 @@
  */
 #define	GPIO(X)		(X)		/* 0 <= X <= (DAVINCI_N_GPIO - 1) */
 
+/* Convert GPIO signal to GPIO pin number */
+#define GPIO_TO_PIN(bank, gpio)	(16 * (bank) + (gpio))
+
 struct gpio_controller {
 	u32	dir;
 	u32	out_data;