ASoC: AMD: Change MCLK to 48Mhz

25Mhz MCLK which was earlier used was of spread type.
Thus, we were not getting accurate rate. The 48Mhz system
clk is of non-spread type and we are changing to it to get
accurate rate.

Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>