arch-arm: move serialize and unserialize definition to cpp file

Change-Id: I9ac64184d3fe36617f474a714b228b55b9a90976
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/36115
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed