In before, only one binding driver is allowed. This patch introduces
a new config to support multiple binding drivers. The first use case
is to allow SR-IOV binding to be co-existed with other binding.
* Rename the config 'driver' to 'default_driver' in 'binding' group.
This is for making it clear that it is allowed to have more than
one type of bindings.
* Introduce a new config called 'enabled_drivers'.
* Allow client to pass a driver name to port_bind and port_unbind.
If this parameter is None, kuryr will load the default driver.
Partial-Implements: blueprint sriov-binding
Change-Id: I14b23379de9f2459ba97d5d82dfdb51553370cb1
da736d115b