fix(mavlink): accept NAV_TAKEOFF param1 on multicopters

[datlt4]

Strict command-parameter validation added in #27541 rejects MAV_CMD_NAV_TAKEOFF when an unsupported param is set. QGroundControl sends param1 (minimum pitch) = -1 on multicopter takeoff, which is non-zero/non-NaN, so commands were silently denied (MAV_RESULT_DENIED with no log) on MC airframes and QGC guided takeoff stopped working.

Extend the NAV_TAKEOFF override to include VEHICLE_MC so param1 is accepted and ignored on multicopters, matching FW/VTOL handling.

[github-actions]

🔎 FLASH Analysis

px4_fmu-v5x [Total VM Diff: -16 byte (-0 %)]

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  -0.0%      -2  [ = ]       0    .debug_info
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  -0.0%     -16  -0.0%     -16    .text
    -1.5%      -4  -1.5%      -4    MavlinkStreamAutopilotStateForGimbalDevice::send()
    -5.0%      -4  -5.0%      -4    mavlink_cmd_params::_find_mask()
    -0.0%      -8  -0.0%      -8    [section .text]
  +0.0%     +48  -0.0%     -16    TOTAL

px4_fmu-v6x [Total VM Diff: -16 byte (-0 %)]

    FILE SIZE        VM SIZE    
 --------------  -------------- 
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  -0.0%      -2  [ = ]       0    .debug_info
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    [DEL]      -6  [ = ]       0    [Unmapped]
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  -0.0%     -16  -0.0%     -16    .text
    -1.5%      -4  -1.5%      -4    MavlinkStreamAutopilotStateForGimbalDevice::send()
    -5.0%      -4  -5.0%      -4    mavlink_cmd_params::_find_mask()
    -0.0%      -8  -0.0%      -8    [section .text]
  +0.0%     +40  -0.0%     -16    TOTAL

Updated: 2026-07-09T18:09:58

[MaEtUgR]

@datlt4 Ha, I haven't seen your pull request but we came to a similar conclusion, I just did a few more changes in #27899

I guess we can merge yours as a hotfix while mine gets reviewed.

[MaEtUgR]

Hotfix to have PX4 takeoff usable again with QGC.