dev-arm: Cpu interface groupEnabled check for global enable

dev-arm: Cpu interface groupEnabled check for global enable

Gicv3CPUInterface::groupEnabled should check for global enable flags at
distributor level:
- Gicv3Distributor.EnableGrp0
- Gicv3Distributor.EnableGrp1S
- Gicv3Distributor.EnableGrp1NS

Change-Id: I1c855b0e4c2bc8f1cd0a8f086b9450f516177b08
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20617
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>