ASoC: rt5665: Convert to use GPIO descriptors

ASoC: rt5665: Convert to use GPIO descriptors

The RT5665 driver has some stub support for GPIO descriptors
going back to the initial driver commit, where there are
two GPIO descriptors for the LDO and headphone detection
defined in the device state. Well, let's make use of the
descriptor properly.

We remove the global GPIO number from the platform data,
but it is still possible to create board files using GPIO
descriptor tables, if desired.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230817-descriptors-asoc-rt-v2-2-02fa2ca3e5b0@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>