ASoC: PCM_RATE: Check for KNOT and CONTINUOUS flags

For ASoC, if either CPU or CODEC driver has set the flag, the MACHINE driver
should be given a chance to figure out if the dai, that set the flag, can
accomodate a rate that it does not explicitly specify but is specified
by the dai at the other end of the link.

Signed-off-by: Jassi Brar <jassi.brar@samsung.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>