Remove sgabios.bin workaround
Remove sgabios.bin workaround

The bug has been fixed since a while, also in recent distributions,
for example Ubuntu 20.04, the sgabios.bin ROM is provided directly
by qemu-system-data as an actual file under /usr/share/qemu and
it conflicts with the one provided by sgabios, so removing the
workaround is actually needed to prevent failures.

Change-Id: Ib5f23dbd8839a0927418692054f4ed4abd76babc

nawawi/openstack,openstack-dev/devstack,openstack-dev/devstack,nawawi/openstack