LU-15795 lbuild: enable KABI

LU-15795 lbuild: enable KABI

Enable build kabi and clean up kmodtool patch

Lustre-change: https://review.whamcloud.com/47507
Lustre-commit: TBD (from 03fc87a2ba08e5c4b8b8787f19b4e736d2752fae)

Test-Parameters: trivial fstype=ldiskfs clientdistro=el8.5 serverdistro=el8.5
Test-Parameters: trivial fstype=ldiskfs clientdistro=el8.6 serverdistro=el8.6

Change-Id: I16d54af0004c4ddc1cc5e6acca81e4aa89a1a1c1
Signed-off-by: Minh Diep <mdiep@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/48486
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>