ACPI: battery: Rename extensions to hook in messages

ACPI: battery: Rename extensions to hook in messages

This functionality is called "hook" everywhere in the code.
For consistency call it the same in the log messages.

The power supply subsystem is about to get its own extension
functionality. While the two are closely related and will be used
together, the current wording leaves room for misinterpretation.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://patch.msgid.link/20241205-power-supply-extensions-v5-1-f0f996db4347@weissschuh.net
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>