zynq: Enable dcache support

Enable dcache.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/cpu/armv7/zynq/cpu.c b/arch/arm/cpu/armv7/zynq/cpu.c
index 9af340e..c771759 100644
--- a/arch/arm/cpu/armv7/zynq/cpu.c
+++ b/arch/arm/cpu/armv7/zynq/cpu.c
@@ -46,3 +46,11 @@
 	while (1)
 		;
 }
+
+#ifndef CONFIG_SYS_DCACHE_OFF
+void enable_caches(void)
+{
+	/* Enable D-cache. I-cache is already enabled in start.S */
+	dcache_enable();
+}
+#endif