LU-14395 kernel: kernel update RHEL7.9 [3.10.0-1160.15.2.el7]

LU-14395 kernel: kernel update RHEL7.9 [3.10.0-1160.15.2.el7]

Update RHEL7.9 kernel to 3.10.0-1160.15.2.el7.

Change debuginfo download location since debuginfo.centos.org
does not provide kernel-debuginfo-common anymore.

The patch also reverts the following fix from RHEL 7.9 kernel
since version 3.10.0-1160.8.1.el7:

- [kernel] timer: Fix lockup in __run_timers() caused by
  large jiffies/timer_jiffies delta (Waiman Long) [1849716]

The above fix caused Hard LOCKUP kernel panic.

Test-Parameters: clientdistro=el7.9 serverdistro=el7.9
Change-Id: Icdd9e8bf4bd595dece266f6c5a9b0de344781a93
Signed-off-by: Jian Yu <yujian@whamcloud.com>
Signed-off-by: Minh Diep <mdiep@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/41902
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>