OE ARMv8 pre-built images needs few packages to run tests

[Naresh Kamboju]

FVP pre-built image is missing few packages
http://snapshots.linaro.org/openembedded/pre-built/vexpress64/latest

I have checked with these three images and found that below listed packages are missing.
- vexpress64-openembedded_minimal-armv8-gcc-4.8_20131113-523.img.gz
- vexpress64-openembedded_leg-java-armv8-gcc-4.8_20131113-523.img.gz
- vexpress64-openembedded_lamp-armv8-gcc-4.8_20131113-523.img.gz

Following modules/commands/packages are needed for running KVM /qemu-system-aarch64 on FVP models.
- modprobe nbd
- brctl
- tunctl
- hackbench

you may refer following test case script for more information
* https://git.linaro.org/gitweb?p=qa/test-definitions.git;a=summary
  - openembedded/kvm.yaml
  - common/scripts/kvm/test-kvm.sh
  - common/scripts/kvm/test-host.sh
  - common/scripts/kvm/test-rt-tests.sh

[Chase Qi (chase-qi)]

Migrated to bugzilla: https://bugs.linaro.org/show_bug.cgi?id=505