merge xf86-video-amdgpu-1.3.0, xf86-video-ati-7.9.0,
xf86-video-nouveau-1.0.15, and xf86-video-openchrome-0.6.0.

merge xf86-video-openchrome 0.3.3.

Remove a couple '#ifdef linux's to let the driver use optimized memcpy
functions on NetBSD for video copy. Gives nearly 2x performance on my
test system (previously "kernel" memcpy was always used):

CHROME(0): Benchmarking video copy. Less time is better.
CHROME(0): Timed libc YUV420 copy... 3000272. Throughput: 315.6 MiB/s.
CHROME(0): Timed kernel YUV420 copy... 3024946. Throughput: 313.0 MiB/s.
CHROME(0): Timed SSE YUV420 copy... 1591352. Throughput: 595.0 MiB/s.
CHROME(0): Timed MMX YUV420 copy... 2566279. Throughput: 369.0 MiB/s.
CHROME(0): Ditching 3DNow! YUV420 copy. Not supported by CPU.
CHROME(0): Timed MMX2 YUV420 copy... 1696662. Throughput: 558.1 MiB/s.
CHROME(0): Using SSE YUV42X copy for video.

initial import of xf86-video-openchrome-0.2.904