Use bus_space_set_region_4 instead of looping over bus_space_write_4, and remove some includes.
Use bus_space_set_region_4 instead of looping over bus_space_write_4,
and remove some includes.

ok patrick@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars