The patch below removes the MAINTAINERS entry for the removed comx
driver.

Additionally, the following comx header files could be removed:
  drivers/net/wan/mixcom.h
  drivers/net/wan/hscx.h
  drivers/net/wan/munich32x.h
  drivers/net/wan/falc-lh.h

I've double-checked that none of them are used by any other driver.