ext: Fix SST Documentation links

This documentation links to v21-2 resources. This is incorrect, they
should point towards v22-0 resources. This patch fixes this.

Change-Id: I0e4868327e0b216619e524c2329f57bbe40d3eae
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/61712
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
1 file changed