Input: pxa27x_keypad - include linux/of.h header

'of_match_ptr' is defined in linux/of.h. Include it explicitly.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/pxa27x_keypad.c

@@ -27,6 +27,7 @@
 #include <linux/err.h>
 #include <linux/input/matrix_keypad.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>