dev-arm: Fix WalkCache stats

The WalkCache stats are wrongly using the legacy framework.
With this patch we are registering those to the hierarchical structure.

As we need to pass the Stats::Group parent at construction time,
we are replacing 2d arrays with Vector2d for count stats and using a flat
vector of pointers for the Formula stats

Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Change-Id: I8992bc262a376e4e81a4d608c11dff6902e0a01d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/42984
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed