ASoC: cs35l35: Add additional delay for reset

Very fast systems may violate the minimum constraints for time the reset
line needs to remain low, or communicate with the device too soon after
releasing the reset. Fix this by adding some delays in to allow the chip
to properly reset, also factor out the reset into a function as it is
likely it will be re-used in later additions to the driver.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Paul Handrigan <Paul.Handrigan@cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>