pinctrl/abx500: add AB8500 sub-driver

This adds a subdriver for the AB8500 pinctrl portions.
As the pin controller (also the ABx500 controllers) is an
inherent part of the SoC and will prevent boot if not
available, select this from the Ux500 SoC Kconfig.

Acked-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index ba3038c..367556f 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -33,6 +33,10 @@
 	help
 	  Select this to enable the ABx500 family IC GPIO driver
 
+config PINCTRL_AB8500
+	bool "AB8500 pin controller driver"
+	depends on PINCTRL_ABX500 && ARCH_U8500
+
 config PINCTRL_AT91
 	bool "AT91 pinctrl driver"
 	depends on OF