As described in commit commit 891a700759 ("lantiq: enable second VPE
on Fritz!Box 7412"):
The AVM Fritz!Box 7412 does not use the VMMC part of the Lantiq chip but
rather a proprietary solution based on the DECT chip for the FXS ports.
We can remove last traces of vmmc in dts.
Signed-off-by: Aleksander Jan Bajkowski <A.Bajkowski@stud.elka.pw.edu.pl>