drm/i915: Introduce intel_cpu_info.c for CPU IDs

drm/i915: Introduce intel_cpu_info.c for CPU IDs

Having similar naming convention in intel-family.h and intel_device_info.h
results in redefinition of a few platforms. Define CPU IDs in its own file
to avoid this.

v3: Move file out of gt directory, add kernel doc (Riana)
    Rephrase file description (Jani)

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241211115952.1659287-4-raag.jadav@intel.com