intel_adsp: ace20_lnl: Add I2S clock source dts

The I2CLCTL_MLCS setting was recently added to MTL
platform. LNL has these registers in separate space, therefore
new field is added to intel,ssp-dai.yaml and appropraite definitions
to LNL device tree.

Signed-off-by: Jaroslaw Stelter <Jaroslaw.Stelter@intel.com>