qapi: Consistently permit any case in downstream prefixes

We require lowercase __RFQDN_ downstream prefixes only where we
require the prefixed name to be lowercase.  Don't; permit any case in
__RFQDN_ prefixes anywhere.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210323094025.3569441-13-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
1 file changed