ASoC: fsl: clarify ac97 dependency

ASoC: fsl: clarify ac97 dependency

A new randconfig build failure shows that the fsl-asoc-card module
must not be built-in when the AC97 driver is a loadable module:

sound/built-in.o: In function `fsl_asoc_card_late_probe':
:(.text+0x571d8): undefined reference to `snd_ac97_update_bits'

I couldn't come up with a nice solution, so this adds another dependency
on "X || !X", which is the Kconfig way of saying that we have an
optional dependency on something that might be a loadable module.

Fixes: 87c649eada2e ("ASoC: fsl-asoc-card: add AC'97 support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>