Importing sys/dev/videomode

NetBSD provides an in-kernel EDID parser, validator, and printer
along with other useful functions. This code will be re-used by
the Minix fb driver as it is a complete and well tested
implementation.

This commit contains a pristine copy of the sources from NetBSD.
As this is kernel code and not a library or userland program,
changes to get it working in Minix will need to be made in a
future commit.

Change-Id: I46fe3005d9957cd90d4972030ddcce7bc3bd7924
fb: auto-configure with EDID

Use EDID when available to configure the frame buffer driver with
good settings for the attached display.

Change-Id: I69a78155a93e55ffa1ca3ff6621a879a56cdbceb
splash: framebuffer test program

Change-Id: I7e045a4c6cec476615057f46f530693c0a2a17e0
splash: use parameters provided by the fb driver

Certain parameters, such as screen resolution, differ between
monitors. Enhance the splash program to dynamically configure
itself.

Change-Id: I49b0a3704decb7cb4633a1ee424b0419a1d67cf0