kernel/linux: longterm kernel location changed

The location of the longterm Linux kernels on FTP has changed.
Here is a simple (but not very versatile) fix.

Signed-off-by: "Björn A. Herwig" <herwig@gdsys.de>
[yann.morin.1998@anciens.enib.fr: make it generic/versatile]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 reporter_name="Alexander BIGGA"

 reporter_url="http://sourceware.org/ml/crossgcc/2008-07/msg00000.html"

 reporter_comment=""