mb/google/volteer/var/elemi: use devtree aliases for PMC MUX connectors
refer to cb:45878
Now that soc_get_pmc_mux_device() is gone, the PMC MUX connector devices
can be hooked up together via devicetree aliases.
BUG=b:
174735512
BRANCH=volteer
TEST=build and type-c display work
Change-Id: I0bf84e2691856c9760d8fa9b6d853b04be10390a
Signed-off-by: Wisley Chen <wisley.chen@quantatw.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48268
Reviewed-by: YH Lin <yueherngl@google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Frans Hendriks <fhendriks@eltan.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>