valgrind: make run-ptest better

valgrind: make run-ptest better

There were warnings about non-existent files when there was
a duplicate in the remove-for-aarch list and the non-deterministic lists
so check if the files still exists before trying to deal with it.

Also restore the tests in the opposite order that they were hidden.

Signed-off-by: Randy MacLeod <Randy.MacLeod@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>