ASoC: SDCA: Add PDE verification reusable helper

ASoC: SDCA: Add PDE verification reusable helper

  Implement sdca_asoc_pde_ensure_ps() helper function to poll for PDE
power state transitions. Per SDCA specification, after writing
REQUESTED_PS, drivers must poll ACTUAL_PS until the target power state
is reached.

Changes include:
- Add sdca_asoc_pde_ensure_ps() to handle ACTUAL_PS polling with
  support for device-specific delay tables or default intervals
- Export function via sdca_asoc.h for use by SDCA-compliant drivers
- Refactor entity_pde_event() in sdca_asoc.c to use the helper

Signed-off-by: Niranjan H Y <niranjan.hy@ti.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Link: https://patch.msgid.link/20260505111806.2280-2-niranjan.hy@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>