new-bus: Remove the 'type' argument from BUS_MAP/UNMAP_RESOURCE

The public bus_map/unmap_resource() API still accepts both forms, but
the internal kobj methods no longer pass the argument.
Implementations which need the type now use rman_get_type() to fetch
the value from the allocated resource.

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D44129