branches: 1.1.10;
Add genfb(4) driver for mac68k grfbus.
1, 2, 4, 8, 15, and 32 color-depths are supported.

ANSI colors on console are functional for depth >= 4.

Graphic applications based on wsfb API should work, provided
they can correctly handle fbi_fboffset and your color depth.

wsfb driver of Xorg 1.20 and mlterm-fb (framebuffer version of
x11/mlterm) work fine for depth == 1 || depth >= 8.

For depth == 8 (256 colors), graphic applications require
colormap callback, which is currently supported for some
internal graphic adapters, and only Civic (found on Quadra
AV series) was tested. Register definition and its usage are
taken from Linux. You can easily support other adapters if
Linux supports that.

Have fun, and any problem reports are welcomed!