tda19988: driver for the TDA19988 HDMI Transmitter

Change-Id: Ia7750df3dd4ec4bd68624c800a0241c70eea7ca4
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
videomode: port from NetBSD to Minix.

 - Use standard headers instead of NetBSD kernel headers.
 - Define macros for missing functions aprint_debug, abs.
 - Other minor fixes to get edid.c, pickmode.c, vesagtf.c to
   compile and link with the Minix frame buffer driver.

Change-Id: Ib1a2295aa51e1564398f93bcef781d1976da96df
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