Add additional Amazon buildslaves
Add additional Amazon buildslaves

Originally the kernel.org builders used the same buildslave as the
Amazon builder.  While functional this resulted in very long build
times, to avoid this add dedicated builders.

Additionally, update to use the latest Amazon AMI.

Signed-off-by: Brian Behlendorf <32d50ad1e384dcb9a5bf7e40fa470df5dabaf348@llnl.gov>

zfsonlinux/zfs-buildbot,zfsonlinux/zfs-buildbot,gmelikov/zfs-buildbot,gmelikov/zfs-buildbot