nvme: Add helper function to parse 16-bit comma separated list

nvme: Add helper function to parse 16-bit comma separated list

In copy command, nlbs is declared as __u16. While parsing command line argument,
it is typecast to integer pointer. So nlbs[1], nlbs[3], nlbs[5], ... are stored
as zero after getting parsed. Therefore it is passing wrong value to controller.
Hence, adding a helper function to parse the 16-bit comma separated list

Signed-off-by: Francis Pravin Antony Michael Raj <francis.michael@solidigm.com>
Signed-off-by: Jonathan Derrick <jonathan.derrick@solidigm.com>