ASoC: hdmi-codec: Allow drivers to restrict sample sizes.

Currently hdmi client drivers does have means to limit the
sample sizes that it can only support. Having formats parameter
option would solve this.

This issue was noticed on DB410c board when adv7511 hdmi codec driver
failed to play a 32 bits audio samples, as it does not support them.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>