Ensure that whatever ran before us leaves the WM835x with a sane default
audio interface configuration as we do not override the companding,
loopback or tristate settings and do not reset the chip at startup (as it
is a PMIC).

Reported-by: Keiji Mitsuhisa <Keiji.Mitsuhisa@wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>