Use compass helper functions for hwdef-defined compass probes

[peterbarker]

Well, Claude was happy.

● Based on my comprehensive analysis of the generated hwdef.h files, I don't see any problems with your changes. Here's what I found:

  Summary of Changes

  Your modifications correctly convert compass probe definitions from the old add_backend format to new wrapper functions:

  Old format:
  add_backend(DRIVER_XXX, AP_Compass_XXX::probe(GET_I2C_DEVICE(bus,addr), external, rotation))

  New format:
  probe_i2c_dev(DRIVER_XXX, AP_Compass_XXX::probe, bus, addr, external, rotation)

  Verification Results

  1. Correct handling of different probe signatures:
    - Standard compasses (HMC5843, IST8310, RM3100, etc.): Use 5-parameter probe_i2c_dev/probe_spi_dev with external flag
    - Special compasses (LSM303D, AK8963 direct): Correctly use 4-parameter "noexternal" variant
    - MPU/ICM auxiliary compasses (AK8963 via MPU9250, AK09916 via ICM20948): Use dedicated wrapper functions
  2. Syntax validation:
    - All 315 compass probe lines were converted (matched count)
    - All parentheses are balanced
    - All lines end with RETURN_IF_NO_SPACE;
    - No malformed syntax detected
  3. Wrapper function existence:
    - Verified all wrapper functions exist in libraries/AP_Compass/AP_Compass.cpp (lines 1613-1656)
    - Confirmed overloaded versions handle both standard and "noexternal" probe signatures
  4. Sample checks across board types:
    - Pixhawk variants: ✓
    - Cube variants: ✓
    - Peripheral boards: ✓
    - Various compass types (I2C, SPI, auxiliary): ✓

  The changes appear to be production-ready with no issues detected.

Board                    AP_Periph  blimp  bootloader  copter  heli  iofirmware  plane  rover  sub
CubeOrange-periph-heavy  16                *
Durandal                            *      *           *       *                 *      *      *
Hitec-Airspeed           *                 *
KakuteH7-bdshot                     *      *           *       *                 *      *      *
MatekF405                           *      *           *       *                 *      *      *
Pixhawk1-1M-bdshot                  120                128     128               128    120    128
SITL_x86_64_linux_gnu               *                  *       *                 *      *      *
f103-QiotekPeriph        -344              *
f303-MatekGPS            72                *
f303-Universal           -8                *
iomcu                                                                *
revo-mini                           72     *           72      72                72     72     72
skyviper-v2450                                         80
speedybeef4                         *      *           *       *                 *      *      *

A useful test is to use ./Tools/scripts/configure_all.py --copy-hwdef old-hwdefs --stop on master and similarly on this branch and then diff -ur on the two directories to see the difference.

Will be testing on hardware.