LP#1688579 -- remove linux-{gke, aws}-tools-common and linux-{gke, aws}-cloud-tools-common

[Andy Whitcroft]

We are not meant to have more than one linux-tools-common package.
The recent linux-gke and linux-aws packages incorrectly produced
their own conflicting packages.  Firstly remove those from the
packages and mark up linux-tools-common and linux-cloud-tools-common
as equivalent to those packages so that dpkg will allow those
to replace the old linux-{gke,aws}-tools-common packages and
linux-{gke,aws}-cloud-tools-common for existing released kernels.

The first 3 patches apply to aws, azure, and gke and drop the
local *-tools-common packages.  The next two patches apply to the
master branch and annotate its *-tools-common packages so they are
sharable.  The final patch prevents any further derivative kernels
from creating these packages.

Proposing for SRU to xenial.

-apw