xstroke: mark as deprecated

xstroke is just a tarball on the avr32linux.org site, the 0.6 version
has been released in April 2004, so we can consider the upstream to be
dead. So let's mark this package as deprecated.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>