pinctrl: move CONFIG_PINCTRL to drivers/Makefile

Kbuild should descend into drivers/pinctrl/ only when CONFIG_PINCTRL
is enabled because everything under that directory depends on
CONFIG_PINCTRL.

We can avoid the conditional, ifeq ($(CONFIG_OF),y) ... endif.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/Makefile b/drivers/Makefile
index b64b49f..e4b260e 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -11,7 +11,7 @@
 obj-$(CONFIG_GENERIC_PHY)	+= phy/
 
 # GPIO must come after pinctrl as gpios may need to mux pins etc
-obj-y				+= pinctrl/
+obj-$(CONFIG_PINCTRL)		+= pinctrl/
 obj-y				+= gpio/
 obj-y				+= pwm/
 obj-$(CONFIG_PCI)		+= pci/