mem-cache: Update default prefetch options.

Update the default prefetch options to achieve out-of-the box
prefetcher performance closer to that which a typical user would
expect. Configurations that set these parameters explicitly will be
unaffected.

The new defaults were identified as part of work on gem5 prefetchers
undertaken by Nikolaos Kyparissas while on internship at Arm.

Change-Id: Ia6c1803c86e42feef01de40c34d928de50fe0bed
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

src/mem/cache/prefetch/Prefetcher.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2012, 2014, 2019, 2023 ARM Limited
+# Copyright (c) 2012, 2014, 2019, 2023-2024 Arm Limited
 # All rights reserved.
 #
 # The license below extends only to copyright in the software and shall
@@ -79,7 +79,7 @@ class BasePrefetcher(ClockedObject):
         "Notify the hardware prefetcher on every access (not just misses)",
     )
     prefetch_on_pf_hit = Param.Bool(
-        False,
+        True,
         "Notify the hardware prefetcher on hit on prefetched lines",
     )
     use_virtual_addresses = Param.Bool(