ASoC: fsl_xcvr: Use regmap for PHY and PLL registers

ASoC: fsl_xcvr: Use regmap for PHY and PLL registers

Define regmap for PHY and PLL registers, the PHY and PLL
registers are accessed by AI interface in controller.

So that driver can use regcache to recover registers
after suspend and resume.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://patch.msgid.link/20241127030035.649219-2-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>