Remove phyp driver

Remove phyp driver

The phyp driver was added in 2009 and does not appear to have had any
real feature change since 2011. There's virtually no evidence online
of users actually using it. IMO it's time to kill it.

This was discussed a bit in April 2016:
https://www.redhat.com/archives/libvir-list/2016-April/msg01060.html

Final discussion is here:
https://www.redhat.com/archives/libvir-list/2019-December/msg01162.html

Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>