LU-9121 lnet: Add the kernel level Marshalling API

LU-9121 lnet: Add the kernel level Marshalling API

Given a UDSP, Marshal the UDSP pointed to by udsp
into the memory block that is allocated from userspace.

Change-Id: I325c977fd9c902f7ee31fceaaf07abf27ef7391e
Test-Parameters: trivial testlist=lnet-selftest,sanity-lnet
Signed-off-by: Sonia Sharma <sharmaso@whamcloud.com>
Signed-off-by: Amir Shehata <ashehata@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/34403
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>