mb/intel/coffeelake_rvp: Stop using headers for HDA verbs
One of the variants lacks an hda_verb.h, and hda_verb.c can't be built.
Follow-up changes will make mainboard hda_verb.c files always get built
through AZALIA_PLUGIN_SUPPORT, and breaks building this contraption.
Turn the headers into standalone compilation units to prevent this
issue. Since they contain definitions, including them from multiple
compilation units wasn't a good idea anyway.
Change-Id: I00d968563539a4e1b8d1e12145293439d8358555
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48360
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>