Fix dcache_tb (and add dump of victim way to dcache)

Fix dcache_tb (and add dump of victim way to dcache)

It bitrotted... more signals need to be initialized. This also adds
a lot more accesses with different timing conditions allowing to
test cases of hit during reloads, hit with reload formward, hit on idle
cache etc...

It also exposes a bug where the cache miss caused by the read of 0x140
uses the same victim way as previous cache miss of 0x40 (same index).

This bug will need to be fixed separately, but at least this exposes it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>