MLBEDSW-5880 Fixed Vela verbose weight flag

*Original weights and encoded NPU weight now report correct size instead
of zero when running vela with --verbose-weights flag
(Code to update the aforementioned attributes was missing)

*Removed print references to unencoded NPU weight size

Change-Id: I6d3e41c04cc46d24eeb54cab89818a35e5df27be
Signed-off-by: Ayaan Masood <Ayaan.Masood@arm.com>