Make NIC configurable

configs/nic.sh

+NET_IF=eno3d1
+NET_IF_MOD=mlx4

irq.sh

@@ -5,14 +5,16 @@ function error() {
 	exit 1
 }
 
+source $EXP_ROOT/configs/nic.sh
+
 cfgfile=$HOME/.irq.sh.config
 cntfile=$HOME/.irq.sh.count
 
 # use tilly01 as default...
 if ! [ -f $cfgfile ]; then
 	cat > $cfgfile <<EOF
-mod: mlx4
-nic: eno3d1
+mod: $NET_IF_MOD
+nic: $NET_IF
 EOF
 	echo -n "async irq:" >> $cfgfile
 	echo -n " 69" >> $cfgfile