Allow nSim targets to have multiple target platforms, using the get-ip.sh
script to select the address in turn, and ip-avail.txt to list the available
IP addresses.

2013-02-04  Jeremy Bennett <jeremy.bennett@embecosm.com>

	* dejagnu/baseboards/arc-linux-aa4.exp: Specify hostname.
	* dejagnu/baseboards/arc-linux-generic.exp: Don't specify hostname
	* dejagnu/baseboards/arc-linux-nsim.exp: Set hostname using
	get-ip.sh script.
	* get-ip.sh, ip-avail.txt: Created.