fix(thresholds): reorder write operations to avoid firmware rejection…

[MatiM72737]

Fixes "Invalid argument" when setting battery charge thresholds

The firmware rejects writes to charge_control_end_threshold if it would temporarily make start ≥ stop.

Solution

• Read current thresholds before changing
• If lowering the stop threshold (new_stop < current_start), write new start first, then new stop
• Otherwise, write new stop first, then new start

Tested on

• Model: t495s (r5 3500U)
• Kernel: 6.18.9.zen1-2
• Works for both increasing and decreasing thresholds