ASoC: rt5677: use 'active low' logic for reset pin

According to the datasheet RESET is active low pin, i.e. system goes to
reset state when pin signal is low.

The previous implementeation was assuming the pin is configured as
'active high' in DTS. Changle the gpio handling code and DTS configuration
to 'active low'.

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>