ARM: SAMSUNG: Fix on inclusion mach/gpio.h on gpiolib.c

Fix on inclusion mach/gpio.h on plat-samsung/gpiolib.c
since new C preprocessor directives.
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
[kgene.kim@samsung.com: minor title and message fix]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/plat-samsung/gpiolib.c

@@ -18,7 +18,7 @@
 #include <linux/kernel.h>
 #include <linux/irq.h>
 #include <linux/io.h>
-#include <mach/gpio.h>
+#include <linux/gpio.h>
 #include <plat/gpio-core.h>
 #include <plat/gpio-cfg.h>
 #include <plat/gpio-cfg-helpers.h>