mem-cache: Fix set and way of sub-entries

mem-cache: Fix set and way of sub-entries

Set and way of sub-entries were not being set previously.
They must be set after the sub-blocks have been assigned
to the main block.

Change-Id: I7b6921b8437b29c472d691cd78cf20f2bb6c7e07
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19669
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>