dev-arm: Remove unused SMMUv3 WalkCache variables

Those were grouped within the stats data structures but were
not actually stats

Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Change-Id: I01bbbada423825ded04a033c0709108e2980ec70
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/42985
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed