arm, imx6, i2c: add I2C4 for MX6DL

add I2C4 modul for MX6DL based boards.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/arch/arm/include/asm/arch-mx6/imx-regs.h b/arch/arm/include/asm/arch-mx6/imx-regs.h
index 35bb005..0d38d45 100644
--- a/arch/arm/include/asm/arch-mx6/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx6/imx-regs.h
@@ -277,6 +277,7 @@
 #define UART3_BASE                  (AIPS2_OFF_BASE_ADDR + 0x6C000)
 #define UART4_BASE                  (AIPS2_OFF_BASE_ADDR + 0x70000)
 #define UART5_BASE                  (AIPS2_OFF_BASE_ADDR + 0x74000)
+#define I2C4_BASE_ADDR              (AIPS2_OFF_BASE_ADDR + 0x78000)
 #define IP2APB_USBPHY1_BASE_ADDR    (AIPS2_OFF_BASE_ADDR + 0x78000)
 #define IP2APB_USBPHY2_BASE_ADDR    (AIPS2_OFF_BASE_ADDR + 0x7C000)