video: Remove nvidiafb and rivafb

video: Remove nvidiafb and rivafb

Bug-Debian: https://bugs.debian.org/383481
Forwarded: no

These drivers contain register programming code provided by the
hardware vendor that appears to have been deliberately obfuscated.
This is arguably not the preferred form for modification.

These drivers are also largely redundant with nouveau.  The RIVA 128
(NV3) is not supported by nouveau but is about 15 years old and
probably discontinued 10 years ago.

Gbp-Pq: Topic debian/dfsg
Gbp-Pq: Name video-remove-nvidiafb-and-rivafb.patch