dev-arm: Setup TC/ISA at construction time of Gicv3CPUInterface

We should initialize them as soon as possible to make sure
any Gicv3CPUInterface method uses a valid reference

Change-Id: I8fffebdab9136a9027c4f61bb9413e97031e1969
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/65291
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
4 files changed