website: Do not use ALPHA as an example

ALPHA has been removed in gem5-20

Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Change-Id: I3548a44a2773d13af8f76141959b1d2f61559812
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/43705
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: Bobby R. Bruce <bbruce@ucdavis.edu>
8 files changed