LU-9121 lnet: Add info on udsp to lnetctl man page

LU-9121 lnet: Add info on udsp to lnetctl man page

Adding description of UDSP commands to lnetctl man page.
Listing each UDSP rule type with specific parameters.
Adding some examples of UDSP commands.

Test-Parameters: trivial testlist=lnet-selftest,sanity-lnet
Signed-off-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Change-Id: I1bde8a4da217c9ba89f31b5d9a1e7d26658bfb40
Reviewed-on: https://review.whamcloud.com/38698
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Amir Shehata <ashehata@whamcloud.com>