ASoC: mediatek: Check for error clk pointer

Yes, you are right and now the return code depending on the
init_clks().

Fixes: 6078c651

 ("soc: mediatek: Refine scpsys to support multiple platform")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/20211222015157.1025853-1-jiasheng@iscas.ac.cn


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