ASoC: tegra: Add AHUB writeable_reg for RX holes

ASoC: tegra: Add AHUB writeable_reg for RX holes

Add writeable_reg callbacks for Tegra210/186 AHUB RX registers so the
flat cache only treats valid RX locations as writable, avoiding holes
in the register map.

Fixes: 16e1bcc2caf4 ("ASoC: tegra: Add Tegra210 based AHUB driver")
Signed-off-by: Sheetal <sheetal@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://patch.msgid.link/20260123095346.1258556-2-sheetal@nvidia.com
Signed-off-by: Mark Brown <broonie@kernel.org>