link/graphics: Add support for EDID

This code is taken from an EDID reader written at Red Hat.

The key function is
int decode_edid(unsigned char *edid, int size, struct edid *out)

Which takes a pointer to an EDID blob, and a size, and decodes it into
a machine-independent format in out, which may be used for driving
chipsets. The EDID blob might come for IO, or a compiled-in EDID
BLOB, or CBFS.

Also included are the changes needed to use the EDID code on Link.

Change-Id: I66b275b8ed28fd77cfa5978bdec1eeef9e9425f1
Signed-off-by: Ronald G. Minnich <rminnich@google.com>
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: http://review.coreboot.org/2837
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
5 files changed