qdev: Move UUID property to qdev-properties-system.c

qdev: Move UUID property to qdev-properties-system.c

Only softmmu code uses DEFINE_PROP_UUID, and it currently depends
on error_set_from_qdev_prop_error().  Move it to
qdev-properties-system.c to get out of our way when refactoring
the qdev property system.

We can eventually move it back to the core property system later,
after removing usage of error_set_from_qdev_prop_error().

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20201211220529.2290218-15-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>