ARM: pxa: corgi: use gpio descriptors for audio

The audio driver should not use a hardwired gpio number
from the header. Change it to use a lookup table.

Acked-by: Mark Brown <broonie@kernel.org>
Cc: alsa-devel@alsa-project.org
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>