firmware: add Exynos ACPM protocol driver

firmware: add Exynos ACPM protocol driver

Alive Clock and Power Manager (ACPM) Message Protocol is defined for
the purpose of communication between the ACPM firmware and masters
(AP, AOC, ...). ACPM firmware operates on the Active Power Management
(APM) module that handles overall power activities.

ACPM and masters regard each other as independent hardware component and
communicate with each other using mailbox messages and shared memory.

This protocol driver provides the interface for all the client drivers
making use of the features offered by the APM. Add ACPM protocol support.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20250213-gs101-acpm-v9-2-8b0281b93c8b@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>