ARM: LPC32xx: clock.c: Missing header file

This patch fixes the compiler warnings regarding the EXPORT_SYMBOL usage
Signed-off-by: Roland Stigge <stigge@antcom.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Kevin Wells <kevin.wells@nxp.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/mach-lpc32xx/clock.c

@@ -82,6 +82,7 @@
  *   will also impact the individual peripheral rates.
  */
 
+#include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/errno.h>