kernel-lt from ELRepo vs. GRUB: define default boot kernel


After upgrading my workstation to CentOS 7.5 (1804), I had to upgrade my
kernel from vanilla to kernel-lt from ELRepo. My NVidia GeForce 210
would only work with the driver provided by NVidia, which in turn
required a more recent kernel than 3.0.10. Anyway.

Right now here's all the kernels that I have on my workstation:

[root@alphamule:~] # rpm -qa | grep -i kernel

And here's what I'm currently running:

[root@alphamule:~] # uname -r

I have a Logitech Illuminated USB keyboard, and one of the quirks of
this piece of hardware is that it's unresponsive on boot time. Meaning
when GRUB displays the kernel menu, the arrow keys (or for the matter
any keys) won't work. Which means the only choice I have left is either
boot the default kernel in the list... or go to another office, grab a
standard USB keyboard and plug it in temporarily just to choose the
kernel to boot.

So right now I have two kernels on my machine, the 4.4.129 and the
4.4.131. How do I configure GRUB so that on the next reboot, it defaults
to the 4.4.131 kernel? I knew how to do this with LILO under Slackware,
but GRUB is a very different beast.