ASoC: amd: drop unused Kconfig symbols

ASoC: amd: drop unused Kconfig symbols

Remove the dangling Kconfig references to CLK_FIXED_FCH since they
are not used anywhere else in the kernel source tree.

Fixes: 281ddf62f551 ("ASoC: amd: Kconfig: Select fch clock support with machine driver")
Fixes: d4c750f2c7d4 ("ASoC: amd: acp: Add generic machine driver support for ACP cards")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20251228190542.2482910-1-rdunlap@infradead.org
Signed-off-by: Mark Brown <broonie@kernel.org>