pwm: samsung: Allow Samsung PWM driver to be enabled on Exynos7

To re-use the existing PWM driver for 64-bit ARM based Exynos7 SoC, make
the driver depend on ARCH_EXYNOS along with PLAT_SAMSUNG.
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/Kconfig

@@ -255,7 +255,7 @@ config PWM_ROCKCHIP
 
 config PWM_SAMSUNG
 	tristate "Samsung PWM support"
-	depends on PLAT_SAMSUNG
+	depends on PLAT_SAMSUNG || ARCH_EXYNOS
 	help
 	  Generic PWM framework driver for Samsung.