rt-tests: pip_stress: Add option --usleep

Different hardwares have different threasholds for usleep_val to
reliably trigger an prio inversion, add option --usleep to allow
specifying it at runtime, to facilitate testing of prio inheritance
on different platforms.

Signed-off-by: Shizhao Chen <shichen@redhat.com>
Signed-off-by: John Kacur <jkacur@redhat.com>
2 files changed