MAINTAINERS: Add x86 platform drivers patchwork

Add x86 platform drivers patchwork which has been missing from
MAINTAINERS.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230919123948.1583-1-ilpo.jarvinen@linux.intel.com


Signed-off-by: Hans de Goede <hdegoede@redhat.com>