Battery reporting for peripheral split half is missing

[lehmanju]

The current implementation of BatteryService only reports the current battery state of the central split half. The information from the peripheral is only logged to console.

RMK should report both battery states. I think it is possible because zmk has done this as well zmkfirmware/zmk#764.

I am willing to implement this, but probably wise to wait for #707 .

[lehmanju]

Cool, support for this might land soon in Linux: https://lore.kernel.org/lkml/20251226111019.31243-1-lzampier@redhat.com/

[lehmanju]

its merged 🥳 https://lore.kernel.org/lkml/177393246035.125995.2162038231287893815.b4-ty@kernel.org/