feat(boards/ark): whitelist generic airframes on ARK FMU boards (#27384)

Vendor-specific airframes (Holybro, UVify, ATL, COEX, Bitcraze,
ThunderFly, Applied Aeronautics) are not relevant on the ARK FMU
boards and only consume flash. Add an rc.board_airframes whitelist
to ark_fmu-v6x and ark_fmu-v6s that keeps only the generic
multirotor, fixed-wing, VTOL, and rover frame types.

Flash savings (default variant):
  ark_fmu-v6x:  1965708 -> 1957772 B  (-7936 B,  free 372 -> 8308 B)
  ark_fmu-v6s:  1960212 -> 1945748 B  (-14464 B, free 8108 -> 22572 B)

Signed-off-by: Jacob Dahl <dahl.jakejacob@gmail.com>

boards/ark/fmu-v6s/init/rc.board_airframes

@@ -0,0 +1,29 @@
+# Generic multirotor
+4001_quad_x
+4014_s500
+4050_generic_250
+5001_quad_+
+6001_hexa_x
+7001_hexa_+
+8001_octo_x
+9001_octo_+
+11001_hexa_cox
+12001_octo_cox
+14001_generic_mc_with_tilt
+16001_helicopter
+24001_dodeca_cox
+
+# Generic fixed-wing
+2100_standard_plane
+3000_generic_wing
+
+# Generic VTOL
+13000_generic_vtol_standard
+13030_generic_vtol_quad_tiltrotor
+13100_generic_vtol_tiltrotor
+13200_generic_vtol_tailsitter
+
+# Generic rover
+50000_generic_rover_differential
+51000_generic_rover_ackermann
+52000_generic_rover_mecanum

boards/ark/fmu-v6x/init/rc.board_airframes

@@ -0,0 +1,29 @@
+# Generic multirotor
+4001_quad_x
+4014_s500
+4050_generic_250
+5001_quad_+
+6001_hexa_x
+7001_hexa_+
+8001_octo_x
+9001_octo_+
+11001_hexa_cox
+12001_octo_cox
+14001_generic_mc_with_tilt
+16001_helicopter
+24001_dodeca_cox
+
+# Generic fixed-wing
+2100_standard_plane
+3000_generic_wing
+
+# Generic VTOL
+13000_generic_vtol_standard
+13030_generic_vtol_quad_tiltrotor
+13100_generic_vtol_tiltrotor
+13200_generic_vtol_tailsitter
+
+# Generic rover
+50000_generic_rover_differential
+51000_generic_rover_ackermann
+52000_generic_rover_mecanum