i.MX25: This architecture has a GPIO4 too

Signed-off-by: Timo Ketola <timo@exertus.fi>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/drivers/gpio/mxc_gpio.c b/drivers/gpio/mxc_gpio.c
index f1b1c16..6615535 100644
--- a/drivers/gpio/mxc_gpio.c
+++ b/drivers/gpio/mxc_gpio.c
@@ -41,7 +41,8 @@
 	[0] = GPIO1_BASE_ADDR,
 	[1] = GPIO2_BASE_ADDR,
 	[2] = GPIO3_BASE_ADDR,
-#if defined(CONFIG_MX51) || defined(CONFIG_MX53) || defined(CONFIG_MX6Q)
+#if defined(CONFIG_MX25) || defined(CONFIG_MX51) || defined(CONFIG_MX53) || \
+		defined(CONFIG_MX6Q)
 	[3] = GPIO4_BASE_ADDR,
 #endif
 #if defined(CONFIG_MX53) || defined(CONFIG_MX6Q)