ASoC: SOF: amd: remove unused code

During initial SOF driver bring up on AMD platforms, only DMIC
support was added. As of today, we have a complete SOF solution for
I2S endpoints along with DMIC endpoint.
This code is no longer required.
Remove unused code from RMB and RN platform ACP PCI driver.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Link: https://lore.kernel.org/r/20230403071651.919027-1-Vijendar.Mukunda@amd.com


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