pci: xgene: do not use clk-private.h

The X-Gene PCIe driver consumes clocks and does not provide them.
Replace usage of clk-private.h with clk.h.

Cc: Tanmay Inamdar <tinamdar@apm.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

drivers/pci/host/pci-xgene.c

@@ -16,7 +16,7 @@
  * GNU General Public License for more details.
  *
  */
-#include <linux/clk-private.h>
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/jiffies.h>