Add irqbalance (#599)

irqbalance distributes hardware interrupts across processors. If there is only 1 CPU it will silently exit.
Increases performance in multiprocessor/multicore systems.
Seems to reduce "CPU Stuck" issue with nested virtualization.

images/00-base/Dockerfile

@@ -25,6 +25,7 @@ RUN apk --no-cache add \
     hvtools \
     iproute2 \
     iptables \
+    irqbalance \
     iscsi-scst \
     jq \
     kbd-bkeymaps \