configs, arch-arm: Using AddrRange for Realview mem_regions

configs, arch-arm: Using AddrRange for Realview mem_regions

Physical memory ranges are now saved in Realview objects as pairs of
addresses (start address and size). This patch is substituting them with
a single AddrRange object.

Change-Id: I02d25d557c5c54d062f0dccef8ede45744d0ce6b
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/16206
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>