linux-headers: drop old unsupported 4.{10,11,12,13,15} versions

linux-headers: drop old unsupported 4.{10,11,12,13,15} versions

These versions received their last updated more than three months ago
and are no longer supported according to
https://www.kernel.org/category/releases.html, so drop them and add
legacy entries.

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
[Thomas: select an older kernel headers (4.9) rather than a newer one
(4.14) in the legacy handling of 4.10, 4.11, 4.12 and 4.13.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>