Added targetr for ATOMRC F405 NAVI MINI with blackbox flash storage

[kijan007]

This pull requests adds support for $TARGET_NAME

• [ ] Target complies with docs/policies/NEW_HARDWARE_POLICY.md

The following items have been checked and confirmed working by an INAV developer on actual hardware: (feel free to remove non-relevant items)

• [X] Samples received
• [X] Flash firmware
• [X] Calibrate
• [X] Orientation matches
• [X] Gyro working
• [X] Accel working
• [X] Voltage correct
• [X] Current correct
• [X] Baro working
• [X] Mag I2C Bus
• [ ] Additional I2C2 Buses (Airspeed/other accessories)
• [X] UART1
• [ ] UART2
• [ ] UART3
• [X] UART4
• [ ] UART5
• [ ] UART6
• [ ] UART7
• [ ] UART8
• [ ] Analog Camera working
• [ ] Video Out working
• [ ] OSD working
• [ ] LEDs working
• [ ] Buzzer working
• [X] Motor outputs
• [ ] DShot support on m1-4
• [X] Servo outputs
• [X] Blackbox
• [ ] PINIO1
• [ ] PINIO2
• [ ] PINIO3
• [ ] PINIO4

[mmosca]

Is this supposed to be an official target? Have samples been sent to devs already?