If a mode requested by a consumer is not allowed by constraints
automatically fall back to a higher power mode if possible. This
ensures that consumers get at least the output they requested while
allowing machine drivers to transparently limit lower power modes
if required.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>