LinuxKPI: Implement dma_map_resource/dma_unmap_resource functions

dma_map_resource() and dma_unmap_resource() functions are used to map
and unmap of memory-mapped IO resources so they can be accessed by
the device.

Required by drm-kmod v5.5 to be built.

While for drm-kmod 6.6-lts only amdgpu uses these in one place and
the code apparently has not been exercised a lot it has been around
like this for years. With changing the underlying implementations
bring it into the tree; should we find errors with it they can also
be fixed here.

Bump __FreeBSD version to be able to detect this change.

Obtained from: D30933 (by wulf)
Sponsored by: The FreeBSD Foundation
Reviewed by: dumbbell
Differential Revision: https://reviews.freebsd.org/D49625

(cherry picked from commit a02180cf60a6a0102669b678e9c81ad9f1aa4d91)