migration: check RDMA and capabilities are compatible on both sides

migration: check RDMA and capabilities are compatible on both sides

Depending on the order of starting RDMA and setting capability,
they can be categorized into the following scenarios:
Source:
 S1: [set capabilities] -> [Start RDMA outgoing]
Destination:
 D1: [set capabilities] -> [Start RDMA incoming]
 D2: [Start RDMA incoming] -> [set capabilities]

Previously, compatibility between RDMA and capabilities was verified only
in scenario D1, potentially causing migration failures in other situations.

For scenarios S1 and D1, we can seamlessly incorporate
migration_transport_compatible() to address compatibility between
channels and capabilities vs transport.

For scenario D2, ensure compatibility within migrate_caps_check().

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Message-ID: <20250305062825.772629-3-lizhijian@fujitsu.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>