GCS_MAVLink: remove DIGICAM_CONFIGURE and CONTROL
GCS_MAVLink: DO_DIGICAM_CONFIGURE params to empty

Replacements will be filled in as they are supported
Copter: use DO_DIGICAM_CONTROL instead of DIGICAM_CONTROL
Plane: use DIGICAM_CONTROL instead of DIGICAM_CONTROL
Rover: use DIGICAM_CONTROL instead of DO_DIGICAM_CONTROL