valgrind.supp: move the whitelist file to /qa dir of ceph.git

valgrind.supp: move the whitelist file to /qa dir of ceph.git

This change drops valgrind.supp whitelist file from teuthology
repo and alters the install task to acquire it from /qa dir of
ceph-qa-suite repository.
It's expected the commit will have sibiling in ceph.git moving
the proper valgrind.supp there.

The rationale behind the entire change is duplication of these
files between two repos, their inconsistencies and confusion.

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>