block/rbd: add support for 'mon_host', 'auth_supported' via QAPI
This adds support for three additional options that may be specified
by QAPI in blockdev-add:
server: host, port
auth method: either 'cephx' or 'none'
The "server" and "auth-supported" QAPI parameters are arrays. To conform
with the rados API, the array items are join as a single string with a ';'
character as a delimiter when setting the configuration values.
Reviewed-by: Markus Armbruster <[email protected]>
Signed-off-by: Jeff Cody <[email protected]>