[media] v4l2-tpg-core: drop SYCC, use higher precision 601 conversion matrix

The SYCC Y'CbCr encoding is identical to the 601 encoding. Since the
SYCC define is about to be removed for use in the kernel we need to
drop it in the TPG code as well.

This patch also adds a 4th decimal to the 601 conversion matrix.
That was specified by the sYCC spec and it makes sense to use this
across the board.

[mchehab@s-opensource.com: fix conflicts with LaTeX math expression patch]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>