drm/i915: Add intel_ prefix to struct ip_version

Rename struct ip_version to intel_ip_version to comply with the
naming conventions for structures.

Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221011153851.3781507-1-radhakrishna.sripada@intel.com