cairo: Adapt the license information based on what is being built

cairo: Adapt the license information based on what is being built

If the "trace" PACKAGECONFIG is removed to disable cairo-trace (the
only part of the code licensed as GPL-3.0), we can adapt the licenses
for cairo-dbg and cairo-src so that they do not include
"GPL-3.0-or-later" and thus they can be used also when, e.g., GPL-3.0
is blacklisted in INCOMPATIBLE_LICENSE. Also drop the GPL-3.0 license
text from LIC_FILES_CHKSUM in this case.

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>