ARM: Kconfig update to support additional GPIOs in OMAP5

OMAP5 has 8 GPIO banks so that there are 32x8 = 256 GPIOs.
In order for the gpiolib to detect and initialize these
additional GPIOs and other TWL GPIOs, ARCH_NR_GPIO is set
to 512 instead of present 256.

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Cousson, Benoit <b-cousson@ti.com>
Reported-by: NGovindraj.R <govindraj.raja@ti.com>
Tested-by: NGovindraj.R <govindraj.raja@ti.com>
Signed-off-by: NTarun Kanti DebBarma <tarun.kanti@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

arch/arm/Kconfig

@@ -1581,6 +1581,7 @@ config ARCH_NR_GPIO
 	default 1024 if ARCH_SHMOBILE || ARCH_TEGRA
 	default 355 if ARCH_U8500
 	default 264 if MACH_H4700
+	default 512 if SOC_OMAP5
 	default 0
 	help
 	  Maximum number of GPIOs in the system.