ASoC: AMD: Enable clk in startup intead of hw_params

Some usages only call startup and shutdown without setting hw_params
(e.g. arecord --dump-hw-params). If we don't enable clk in startup, it
will cause ref count error because the clk will be disabled in shutdown.
For this reason, we should move enabling clk from hw_params to startup.

In addition, the hw_params is fixed in this driver(48000 rate, 2
channels, S16_LE format) so we don't need to change the clk rate after
the hw_params is set.

Signed-off-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Acked-by: Akshu Agrawal <akshu.agarawal@amd.com>
Link: https://lore.kernel.org/r/20191126075424.80668-1-yuhsuan@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>