dev-arm: Check for maximum number of supported PE in GICv3

This is currently set to 256

Change-Id: If7bb2847c22f29bfa0cb4ebf4a7984ee43ab4e29
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/+/18390
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed