Cleanup the siihdmi header (which really is pointless to split out...), redefine
the fields for the sii info frame packets, and restructure sizes to be in terms
of registers.
info frame checksumming is defined by the CEA861-E standard, and is not specific
to SII9xxx, so move that into the CEA861 header.
Don't bother allocating the info frame structures off the heap. That causes
unnecessary fragmentation and complexity. Allocate them off the stack as they
are small enough. This also helps keep everything simple.
As a bonus, fixed up the SII HDMI structures and the CEA861 InfoFrame structures
in the process as well. Also clean up the magic number in the AVI InfoFrame
assertion.