staging: clocking-wizard: Include clk.h

This clock provider uses the consumer API, so include clk.h
explicitly.
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c

@@ -19,6 +19,7 @@
  */
 
 #include <linux/platform_device.h>
+#include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/slab.h>
 #include <linux/io.h>