power: supply: bq27xxx: bq27z561: fix invalid AverageEnergy address

bq27z561 currently uses the AveragePower reg, 0x22, for reading both
AveragePower and AvailableEnergy. The technical reference manual does
not mention AvailableEnergy, and it does not make sense to read a
cumulative, always positive, property like AvailableEnergy from a rate
property like AveragePower. Set REG_AE as invalid to fix it.

Fixes: 6f24ff97e323 ("power: supply: bq27xxx_battery: Add the BQ27Z561 Battery monitor")
Signed-off-by: Henrik Grimler <henrik.grimler@axis.com>
Link: https://patch.msgid.link/20260811-bq27z746-v1-5-3a4fa38205cc@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>