ARM: S5P[v210|c100|64x0]: Fix build error

gpio-samsung.h header file introduced by commit 93177be0910c
("ARM: S3C[24|64]xx: move includes back under <mach/> scope")
is required only by S3C[24|64]xx machines. Include them conditionally
to avoid the following build errors for other machine configurations.
drivers/gpio/gpio-samsung.c:35:31: fatal error: mach/gpio-samsung.h: No such file or directory
arch/arm/plat-samsung/pm-gpio.c:22:31: fatal error: mach/gpio-samsung.h: No such file or directory

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/arch/arm/plat-samsung/pm-gpio.c b/arch/arm/plat-samsung/pm-gpio.c
index a9f7a37..dd4c15d0 100644
--- a/arch/arm/plat-samsung/pm-gpio.c
+++ b/arch/arm/plat-samsung/pm-gpio.c
@@ -19,7 +19,10 @@
 #include <linux/io.h>
 #include <linux/gpio.h>
 
+#if defined(CONFIG_ARCH_S3C24XX) || defined(CONFIG_ARCH_S3C64XX)
 #include <mach/gpio-samsung.h>
+#endif
+
 #include <plat/gpio-core.h>
 #include <plat/pm.h>