website: Fix Doxygen links in documentation to new link

Change-Id: Iae91f36065c1fd33287f6b8a071f6d0bf842b39f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/26903
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: Jason Lowe-Power <power.jg@gmail.com>
5 files changed