greybus: svc: clean up link configuration hack at hello

Commit ee2f2074 ("greybus: svc: reconfig APBridgeA-Switch link to
handle required load") added a temporary hack which reconfigures the
link at HELLO by abusing the deferred request processing mechanism.

Restructure the HELLO request processing so that the link-configuration
work is queued before creating the debugfs files and add a comment
explaining why it's there.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20220202113347.1288-4-johan@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>