This changes the way RC is handled for the Mantis:
- The RC values are re-written when arriving over MAVLink. They are
rescaled from 0..4095 to 1000..2000 and the channel bits added to
separate channels. This makes the downstream handling easier.
- Gimbal pitch is moved from Aux1 to Aux2 as that should be the default.
- Aux3 and Aux4 are used for the photo and video trigger.
- The speed button is used as the FLTMODE channel and set to switch
between POSCTL and ALTCTL.
The limits might somewhat match the sensor, guessed based on the
original driver.
The quality is set so that spikes when sitting on the ground are not
used.
Remove params from airframe configs that are just set again
to the param default value or to the value that is
specified in the mc_default, fw_default or vtol_default.
Signed-off-by: Silvan Fuhrer <silvan@auterion.com>