gpio: am43xx: expand gpio support

AM43XX SoCs support up to 192 GPIO signals.
Make this amount available to the driver.

Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>

arch/arm/include/asm/arch-am33xx/gpio.h

@@ -6,7 +6,11 @@
 
 #include <asm/omap_gpio.h>
 
+#ifdef CONFIG_AM43XX
+#define OMAP_MAX_GPIO		192
+#else
 #define OMAP_MAX_GPIO		128
+#endif
 
 #define AM33XX_GPIO0_BASE       0x44E07000
 #define AM33XX_GPIO1_BASE       0x4804C000