drivers/gpio is platform-neutral

Update Kconfig and Makefile in drivers/gpio to discourage inappropriate
addition of platform-specific code.

[akpm@linux-foundation.org: fix tpyo]
Signed-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/gpio/Kconfig

 #
-# GPIO infrastructure and expanders
+# platform-neutral GPIO infrastructure and expanders
 #
 
 config ARCH_WANT_OPTIONAL_GPIOLIB

drivers/gpio/Makefile

-# gpio support: dedicated expander chips, etc
+# generic gpio support: dedicated expander chips, etc
+#
+# NOTE: platform-specific GPIO drivers don't belong in the
+# drivers/gpio directory; put them with other platform setup
+# code, IRQ controllers, board init, etc.
 
 ccflags-$(CONFIG_DEBUG_GPIO)	+= -DDEBUG