ARM: shmobile: r8a7790 PFC support

Add a platform device for the r8a7790 PFC.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig
index ccaea6a..ff674c5 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -53,6 +53,7 @@
 
 config ARCH_R8A7790
 	bool "R-Car H2 (R8A77900)"
+	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARM_GIC
 	select CPU_V7
 	select ARM_ARCH_TIMER