feat: Add Apple Silicon GPU support via IOReport API

[gneitzke]

Add GPU monitoring for Apple Silicon Macs using the IOReport framework and IOHIDEventSystem for temperature readings.

Metrics supported:

• GPU utilization (from GPU Performance States residency)
• GPU power consumption (from Energy Model channel)
• GPU temperature (from IOHIDEventSystem thermal sensors)
• GPU clock speed (from DVFS frequency table + residency weighting)
• Memory usage (unified memory architecture, reports system RAM)

Implementation follows the existing Nvml/Rsmi/Intel backend pattern with init/shutdown/collect<is_init> template functions in a new AppleSilicon namespace under Gpu.

Build system changes:

• Enable GPU_SUPPORT on macOS in both CMakeLists.txt and Makefile
• Link IOReport library on macOS
• Add 'apple' to shown_gpus vendor filter

Closes #955

[aristocratos]

Seems to be working fine on an Mac Mini M1 👍

Would you mind creating RAII wrapper classes for the types that needs CFRelease() and IOObjectRelease().
Would be enough with something simple like two templates that takes any of the types used for either.

There is an PR that already covers this #1470, however this PR is a lot more specific (and easier to parse).
@Ruaneri-Portela would you consider removing the GPU specif parts from your PR and just keep the CPU changes.

[Ruaneri-Portela]

Seems to be working fine on an Mac Mini M1 👍

Would you mind creating RAII wrapper classes for the types that needs CFRelease() and IOObjectRelease(). Would be enough with something simple like two templates that takes any of the types used for either.

There is an PR that already covers this #1541, however this PR is a lot more specific (and easier to parse). @Ruaneri-Portela would you consider removing the GPU specif parts from your PR and just keep the CPU changes.

Hello, no problem for me. I can revert the GPU code.

I can create a GenericCFObject just to hold via RAII using the directives I made in my iokit.c, if @gneitzke doesn't mind he could use this structure in the implementation to be in accordance with RAII

[aristocratos]

@gneitzke Is this generic for all Apple Silicon GPU's (so far)?

[gneitzke]

@gneitzke Is this generic for all Apple Silicon GPU's (so far)?

It should be, I ran it on my m3 max and it works great.

[aristocratos]

Thanks for contributing!