This patch moves the code to select the gpios for jack detection
from rt5677_probe to rt5677_init_irq (called from rt5677_i2c_probe).

It also sets some registers to fix bugs related to jack detection, and
adds some constants and comments to make it easier to understand what
certain register settings are controlling.
Signed-off-by: Ben Zhang <benzh@chromium.org>
Signed-off-by: Fletcher Woodruff <fletcherw@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>