arch: Add setRegOperand in VecRegOperand

VecRegOperand also need setRegOperand method to write back execution
result.

Change-Id: Ie50606014827c14a7219558dd003eb4747231649
Co-authored-by: Xuan Hu <huxuan@bosc.ac.cn>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/67292
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed