/usr/share/ardour4/midi_maps/ is in ardour-data 1:4.6~dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/ardour4/midi_maps/AKAI_MPK61.map
/usr/share/ardour4/midi_maps/DDX3216.map
/usr/share/ardour4/midi_maps/Korg_nanoKONTROL.map
/usr/share/ardour4/midi_maps/Korg_nanoKONTROL2.map
/usr/share/ardour4/midi_maps/Korg_nanoKONTROL2_With_Master.map
/usr/share/ardour4/midi_maps/Korg_nanoKONTROL_Master.map
/usr/share/ardour4/midi_maps/M-Audio_Axiom25.map
/usr/share/ardour4/midi_maps/M-Audio_Axiom61.map
/usr/share/ardour4/midi_maps/M-Audio_Oxygen49.map
/usr/share/ardour4/midi_maps/Novation Impulse 49.map
/usr/share/ardour4/midi_maps/Novation_Impulse61.map
/usr/share/ardour4/midi_maps/Novation_LaunchControl_XL.map
/usr/share/ardour4/midi_maps/Roland_SI-24.map
/usr/share/ardour4/midi_maps/Roland_V_Studio_20.map
/usr/share/ardour4/midi_maps/Yamaha_KX25.map
/usr/share/ardour4/midi_maps/bcf2000.map
/usr/share/ardour4/midi_maps/bcf2000_mackie.map
/usr/share/ardour4/midi_maps/m-audio_oxygen25.map
/usr/share/ardour4/midi_maps/m-audio_oxygen8v2.map
/usr/share/ardour4/midi_maps/midikb_wiimote.map
/usr/share/ardour4/midi_maps/xboard-61.map