bpf_helpers.h: update KVER constants

4.9 and 6.12 are LTS kernels - add them
5.8 is not, and the constant is no longer used - remove it

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <[email protected]>
Change-Id: I1f0d8dd08e331412eaddeaf86b1435f9cf7d15db
1 file changed