ASoC: fsl_mqs: Don't check clock is NULL before calling clk API

Because clk_prepare_enable and clk_disable_unprepare should
check input clock parameter is NULL or not internally, then
we don't need to check them before calling the function.

Fixes: 9e28f653

 ("ASoC: fsl_mqs: Add MQS component driver")
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Link: https://lore.kernel.org/r/743be216bd504c26e8d45d5ce4a84561b67a122b.1592888591.git.shengjiu.wang@nxp.com


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