[PATCH] add CONFIG_GENERIC_GPIO

[PATCH] add CONFIG_GENERIC_GPIO

Most drivers using GPIOs already know they are running on a system that
supports the generic GPIO calls, because of other platform dependencies.
But the generic GPIO-based LED and input button drivers can't know that.

So this patch adds a Kconfig hook, GENERIC_GPIO, to mark the platforms
where <asm/gpio.h> will do the right thing.  Currently that's a bunch of
ARMs, and AVR32; more are on the way.

It also fixes a dependency bug for the gpio button input driver; it was
wrong to start with, now it covers all platforms with GENERIC_GPIO.

Signed-off-by: David Brownell <[email protected]>
Acked-by: Richard Purdie <[email protected]>
Cc: Arnaud Patard <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: pHilipp Zabel <[email protected]>
Cc: Haavard Skinnemoen <[email protected]>
Cc: Dmitry Torokhov <[email protected]>
Cc: Russell King <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>