mem-cache: Change Cache block tag check

mem-cache: Change Cache block tag check

Change tag to address check for compatibility with sector design.
Cache should not use tag, as sector sub-blocks share them, and
it could lead to wrong accesses.

Change-Id: Id1fa26f417595f475c5b5c07ae1f02f5fa0684ba
Reviewed-on: https://gem5-review.googlesource.com/10723
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>