ASoC: Use *-y instead of *-objs in Makefile

Merge series from Takashi Iwai <tiwai@suse.de>:

This is a series of trivial cleanup patches for ASoC to correct
the *-objs suffix in Makefile.  The other ALSA code has been covered
by a previous patch set
  https://lore.kernel.org/r/20240507135513.14919-1-tiwai@suse.de

As was suggested in a patch review, *-objs suffix in Makefile is
basically a wrong use nowadays for kernel driver modules.
They should be replaced with *-y suffix instead.
This is a result of systematic conversions, separated per directory.

Only lightly compile-tested.