Do not set net.inet.ip.{sourceroute,accept_sourceroute} in a vnet jail.
The following warnings were displayed:

 sysctl: net.inet.ip.sourceroute=0: Operation not permitted
 sysctl: net.inet.ip.accept_sourceroute=0: Operation not permitted
Create an interface and support routines for drivers that handle IO pin
multiplexing and configuration based on FDT data.

Reviewed by:	imp