Implement msleep_interruptible() in the LinuxKPI. While at it use pause_sbt()
instead of pause() in the msleep() function to avoid rounding errors when
converting delay values forth and back. Add a guard for a delay value
of zero milliseconds which is undefined.

MFC after: 1 week
Requested by: Johannes Lundberg <johalun0@gmail.com>
Sponsored by: Mellanox Technologies