ASoC: codec/ingenic: Depend on MACH_INGENIC

No need to show the options to build Ingenic-specific drivers on all
MIPS kernel configurations if Ingenic SoCs support is not enabled.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20210123140958.12895-2-paul@crapouillou.net
Signed-off-by: Mark Brown <broonie@kernel.org>