ALSA: ASoC: Add all CODECs Kconfig option

Allow all the CODEC drivers to be built without a machine driver in order
to facilitate testing of subsystem-wide changes and gain better coverage
from automated testing efforts. This also helps things like the generic
OpenFirmware machine driver for PowerPC.

Currently AC97 CODECs are not included since the current setup relies
on having a controller driver available.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>