mfd: Fix ucb1x00 build failure for collie_defconfig

This patch fixes a build failure[1], by adding the missing semaphore.h include

References:
[1] http://kisskb.ellerman.id.au/kisskb/buildresult/2234322/Signed-off-by: NPeter Huewe <peterhuewe@gmx.de>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

drivers/mfd/ucb1x00-core.c

@@ -27,6 +27,7 @@
 #include <linux/mutex.h>
 #include <linux/mfd/ucb1x00.h>
 #include <linux/gpio.h>
+#include <linux/semaphore.h>
 
 #include <mach/dma.h>
 #include <mach/hardware.h>

include/linux/mfd/ucb1x00.h

@@ -12,6 +12,7 @@
 
 #include <linux/mfd/mcp.h>
 #include <linux/gpio.h>
+#include <linux/semaphore.h>
 
 #define UCB_IO_DATA	0x00
 #define UCB_IO_DIR	0x01