ASoC: SOF: amd: Add support for signed fw image loading

Add support for signed firmware code bin and data bin
loading for amd platforms.

Signed-off-by: Venkata Prasad Potturu <venkataprasad.potturu@amd.com>
Link: https://lore.kernel.org/r/20230809123534.287707-2-venkataprasad.potturu@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>