website: Fixed broken link to ISCA 2011 slides

As pointed out by
https://www.mail-archive.com/gem5-users@gem5.org/msg17531.html , the
link to the ISCA 2011 slide was incorrect. This has been fixed.

Change-Id: Ia855c16388a2a0241ff9a75df2357ec1a51a463f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/26363
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: Bobby R. Bruce <bbruce@ucdavis.edu>
1 file changed