ASoC: amd: acp: add missing SND_SOC_AMD_ACP_LEGACY_COMMON flag for ACP70

add missing dependent SND_SOC_AMD_ACP_LEGACY_COMMON flag for ACP70 platform.

Signed-off-by: Syed Saba Kareem <Syed.SabaKareem@amd.com>
Link: https://lore.kernel.org/r/20231116053405.2574081-1-Syed.SabaKareem@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>