feat(systemd): pull 'drm' module unless excluded

[rmetrich]

Changes

Some graphic cards require the drm module to be present to be able to setup the console font (e.g. i915 requires it).

Checklist

• [X ] I have tested it locally
• I have reviewed and updated any documentation if relevant
• I am providing new code and test(s) for it

Manual testing only on a QEMU/KVM

1. Remove plymouth package from the system

2. Set the console font

   # grep FONT /etc/vconsole.conf
   FONT="latarcyrheb-sun32"
   

3. Rebuild the initramfs and verify there is no "drm" module (original state, without this patch)

   # dracut -f
   # lsinitrd --mod | grep drm
   --> nothing
   

4. Reboot and add rd.break to drop to emergency

5. At emergency prompt, confirm the font was not applied (the font is very pixelized)

6. Apply the patch

7. Rebuild the initramfs and verify there is "drm" module

   # dracut -f
   # lsinitrd --mod | grep drm
   drm
   

8. Reboot and add rd.break to drop to emergency

9. At emergency prompt, confirm the font was applied (the font is very pixelized)