[ARM] pxa/akita: use pca953x instead of akita-ioexp

Use generic pca953x which provides gpiolib interface instead of
akita-specific akita-ioexp with non-standard interface to pins.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>