pinctrl/abx500: add AB8540 sub-driver

Add AB8540 sub driver to the ABx500 family, pins, pin groups and
gpio range.

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>
Signed-off-by: Patrice Chotard <patrice.chotard@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinctrl-abx500.h b/drivers/pinctrl/pinctrl-abx500.h
index fe1ccb7..df8e0ff 100644
--- a/drivers/pinctrl/pinctrl-abx500.h
+++ b/drivers/pinctrl/pinctrl-abx500.h
@@ -190,6 +190,19 @@
 
 #endif
 
+#ifdef CONFIG_PINCTRL_AB8540
+
+void abx500_pinctrl_ab8540_init(struct abx500_pinctrl_soc_data **soc);
+
+#else
+
+static inline void
+abx500_pinctrl_ab8540_init(struct abx500_pinctrl_soc_data **soc)
+{
+}
+
+#endif
+
 #ifdef CONFIG_PINCTRL_AB9540
 
 void abx500_pinctrl_ab9540_init(struct abx500_pinctrl_soc_data **soc);