ASoC: rt5645: Add TDM support for rt5650

rt5650 and rt5645 use different register bits for TDM configuration.
This patch modifies rt5645_set_tdm_slot to support both codecs.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>