ASoC: cs42l43: Use fls to calculate the pre-divider for the PLL

Use fls to calculate the pre-divider and input frequency for the PLL,
this is marginally faster than the previous loop.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://msgid.link/r/20240125103117.2622095-7-ckeepax@opensource.cirrus.com


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