This implements support for the GPIO LIB API.  Two calls are still
unimplemented though: irq_to_gpio and gpio_to_irq.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NPaul Mackerras <paulus@samba.org>