ASoC: dapm: add support to pinctrl dapm

Purpose of having pinctrl dapm is to dynamically put the pins in
low power state when they are not actively used by the audio and
saving power.

Without this each driver has to set the pinctrl states, either
during probe or dynamically depending on the callbacks received
from ASoC core.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>