dev-arm: Check for security attribute when writing to ICFGR registers

dev-arm: Check for security attribute when writing to ICFGR registers

This is matching the GICD_ICFGR read; a non secure access to a secure
interrupt should be treated as RAZ/WI

Change-Id: I9e92e03c13fe0474ed139b0ed22cebd5847b9109
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/31615
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>