ext: Avoid content duplication in gem5-SST docs

A brief guide on how to run the gem5 SST example scripts
is already provided in the README file, so there is no need
to copy-paste it in the INSTALL file, which should cover
the building phase only.

Change-Id: I49c677f54450d97a1c8508764e45ab23b4b5fe33
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/53629
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed