drm/intel/pciids: rename i915_pciids.h to just pciids.h

drm/intel/pciids: rename i915_pciids.h to just pciids.h

In preparation of sharing the PCI ID macros between i915 and xe, rename
i915_pciids.h to pciids.h.

Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Tvrtko Ursulin <tursulin@ursulin.net>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/835143845faa5310e4bb58405a8a0848392bbf06.1729590029.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>