power: supply: Add macsmc-power driver for Apple Silicon

power: supply: Add macsmc-power driver for Apple Silicon

This driver provides battery and AC status monitoring for Apple Silicon
Macs via the SMC (System Management Controller). It supports reporting
capacity, voltage, current, and charging status, and modifying the
charging behaviour across multiple generations of SMC firmware.

Signed-off-by: Hector Martin <marcan@marcan.st>
Co-developed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Co-developed-by: Janne Grunau <j@jannau.net>
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Sven Peter <sven@kernel.org>
Co-developed-by: Michael Reeves <michael.reeves077@gmail.com>
Signed-off-by: Michael Reeves <michael.reeves077@gmail.com>
Link: https://patch.msgid.link/20260217-b4-macsmc-power-v7-1-4a4d63664362@gmail.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>