Toyota: set pcm_accel_net when possible

[sshane]

Useful when working on porting this to other cars and having a list of cars that don't have this message

[sshane]

@deanlee does your new CANParser refactor allow checking in cp.vl? I can make this a constant set if not

[deanlee]

@sshane : it support, ReadonlyDict inherits from Mapping, collections.abc.Mapping already provides the default implementations for many dictionary-like methods, including in, values(), items()... Therefore, we only need to implement __getitem__, __iter__, and __len__. Mapping can use them to support other dict methods.