ASoC: loongson: Factor out loongson i2s enable clock functions

There are a few i2s clock enable operations in loongson_i2s_set_fmt(),
convert them to simple helper functions called
loongson_i2s_enable_mclk() and loongson_i2s_enable_bclk().

Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://patch.msgid.link/d6f6c818b0ecee87277f704b6a801cbbf5e712ce.1725844530.git.zhoubinbin@loongson.cn


Signed-off-by: Mark Brown <broonie@kernel.org>