EC2: Set PCIe eject timeout to 0

Since PCIe device detaching is done via API, there is no opportunity
to "press the attention button a second time" and thus the 5 second
timeout mandated by PCIe serves no purpose.

MFC after: 2 weeks
Sponsored by: Amazon

(cherry picked from commit 80febaa1714e897d67a8217edc305a0e81498a6f)