ASoC: mxs-saif: Handle return value of clk_prepare_enable/clk_prepare.

clk_prepare_enable() and clk_prepare() can fail here and
we must check its return value.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>