The three eseries machines have very similar drivers for audio, all
using the mach/eseries-gpio.h header for finding the gpio numbers.

Change these to use gpio descriptors to avoid the header file
dependency.

I convert the _OFF gpio numbers into GPIO_ACTIVE_LOW ones for
consistency here.
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: alsa-devel@alsa-project.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>