graphics/nvidia-drm-kmod: Make distinfo auto-merged on build
Currently, distinfo for graphics/nvidia-drm-*-kmod are required
to be updated manually when whichever of x11/nvidia-driver and
corresponding graphics/drm-*-kmod is upgraded, not to be forgotton
to be updated/committed.
And with graphics/drm-*-kmod part, although the contents of
their distfile always 100% matches, the downloaded filename
differs as of the differences of the method for downloading,
avoiding to simply replace corresponding part of distinfo
with the ones for gaphics/drm-*-kmod.
This change removes existing distinfo from graphics/nvidia-drm-*-kmod
and merges distinfo for x11/nvidia-driver and corresponding
graphics/drm-*-kmod on-the-fly on fetch and cleans up on
clean phase of builds.
This distinfo merges should be sane, as each source distinfo are already
confirmed by their maintainers / committers on commit.
Also includes changes of distfile names for DRM part to match
with graphics/drm-*-kmod to allow auto-merge.
This change depends on D50142 that splits distinfo of x11/nvidia-driver
into master and each legacy ports.
Depends on: D50142