d/t/run-upstream-tests : don't use cpu=max on arm64

d/t/run-upstream-tests : don't use cpu=max on arm64

recent EDK2 introduce the support for LPA2 on arm64,
with cpu=max, QEMU advertises lpa2 support and fails to
run the VM because LPA2 support is not complete or buggy
in EDK2/QEMU.

Using cpu=max on arm64 is not required for the tests and
it is better to use a more conventional cpu model that is
stable. This commit switch cpu to neoverse-n1 for arm64.

Closes: #1128969