i2c: designware_i2c: Include clk.h in the header file

We use struct clk here so really should include this header file to avoid
build errors. Also switch the order of clk.h in the C file to match the
required code style.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ley Foon Tan <ley.foon.tan@intel.com>
Reviewed-by: Jun Chen <ptchentw@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>

drivers/i2c/designware_i2c.c

@@ -4,8 +4,8 @@
  * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
  */
 
-#include <clk.h>
 #include <common.h>
+#include <clk.h>
 #include <dm.h>
 #include <i2c.h>
 #include <pci.h>

drivers/i2c/designware_i2c.h

@@ -7,6 +7,7 @@
 #ifndef __DW_I2C_H_
 #define __DW_I2C_H_
 
+#include <clk.h>
 #include <reset.h>
 
 struct i2c_regs {