It doesn't look like we can get into this code, but make it
more robust and declare two S1G chandefs to be incompatible
unless they're identical.

Link: https://msgid.link/20240129194108.b28fb0644a8c.I9297ada5cf1baf00dbbdf8fcffd1806883489fc9@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>