mx31: add GPIO registers definitions

Added definitions for i.MX31 processor GPIO registers.
Signed-off-by: Ilya Yanok <yanok@emcraft.com>

include/asm-arm/arch-mx31/mx31-regs.h

@@ -86,6 +86,16 @@
 
 #define WDOG_BASE		0x53FDC000
 
+/*
+ * GPIO
+ */
+#define GPIO1_BASE	0x53FCC000
+#define GPIO2_BASE	0x53FD0000
+#define GPIO3_BASE	0x53FA4000
+#define GPIO_DR		0x00000000	/* data register */
+#define GPIO_GDIR	0x00000004	/* direction register */
+#define GPIO_PSR	0x00000008	/* pad status register */
+
 /*
  * Signal Multiplexing (IOMUX)
  */