[SRU][X,B,D,E] update ENA driver for DIMLIB

[Kamal Mostafa]

BugLink: https://bugs.launchpad.net/bugs/1853180

Update the Amazon ENA driver to latest mainline version with dynamic
interrupt moderation supplied by DIMLIB, plus a couple of pending fixes
from the netdev mailing list.

Note: For {Xenial,Bionic,Disco}, this needs bug 1852637
    https://bugs.launchpad.net/bugs/1852637
    ("backport DIMLIB (lib/dim/) to pre-5.2 kernels")
as a prerequisite.

 -Kamal