mx5: Enable dcache

Now that the main i.MX features work fine with dcache enabled, enabled it by
default if CONFIG_SYS_DCACHE_OFF is not defined.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Stefano Babic <sbabic@denx.de>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/cpu/armv7/mx5/soc.c b/arch/arm/cpu/armv7/mx5/soc.c
index 3f5a4f7..98203ba 100644
--- a/arch/arm/cpu/armv7/mx5/soc.c
+++ b/arch/arm/cpu/armv7/mx5/soc.c
@@ -71,6 +71,14 @@
 	return system_rev;
 }
 
+#ifndef CONFIG_SYS_DCACHE_OFF
+void enable_caches(void)
+{
+	/* Enable D-cache. I-cache is already enabled in start.S */
+	dcache_enable();
+}
+#endif
+
 #if defined(CONFIG_FEC_MXC)
 void imx_get_mac_from_fuse(int dev_id, unsigned char *mac)
 {