resources: Add a default value for the PrefetchCache constructor

The spec2006 gem5 configs currently doesn't work due to the
PrefetchCache constructor is called without specifying `options`.
Since `options` is not a required parameter, it's safe to set
`None` as the default value for this parameter.

Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Change-Id: Iacfeb7d1368af80925bdd5e9364807cadf34a568
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-resources/+/37235
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: Bobby R. Bruce <bbruce@ucdavis.edu>
1 file changed
tree: c2377bc3728f2efbc83d2b3765c6e6e645388fd6
  1. README.md
  2. src/