firmware: exynos-acpm: register ACPM clocks pdev

firmware: exynos-acpm: register ACPM clocks pdev

Register by hand a platform device for the ACPM clocks.
The ACPM clocks are not modeled as a DT child of ACPM because:
1/ they don't have their own resources.
2/ they are not a block that can be reused. The clock identifying
   data is reduced (clock ID, clock name and mailbox channel ID)
   and may differ from a SoC to another.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Tested-by: Peter Griffin <peter.griffin@linaro.org> # on gs101-oriole
Link: https://patch.msgid.link/20251010-acpm-clk-v6-3-321ee8826fd4@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>