add gpiolib support ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>

gpio: add static inlines for gpio_request/gpio_free ...

Some drivers use gpio_request/gpio_free. Currently no architecture
has code behind these functions. Provide static inline functions
for these and remvoe the at91 specific inline functions.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

GPIO support ...

adopted Linux gpio code. Implemented for at91sam9. No gpiolib support
yet.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>