common: Adding Mellanox packages support for U12

For ubuntu 12, when using ENABLE_MELLANOX=y directive, infiniband
packages are taken from Mellanox servers instead of Ubuntu's ones.

This patch is hacking the auto-installer from Mellanox to make it work
in our environment :
- managing kernel modules (dkms) in a chroot env
    Modules will be rebooted at boot time not during installation
- avoid packages installation troubles in a chroot
    Some packages should not try to start their services inside the
    chroot

This patch is a preliminary work and might be extended to more distro if
needed.

Using Mellanox's drivers could help at getting new features or better
hardware support on some boards.

Note this feature makes the OS bigger as we do integrate kernel headers,
gcc & dkms stuff.

Note also this feature shall not be enabled for pxe or health-check since
it will make the OS too big while we only need detection stuff working.
Makefile: Adding Infiniband support for benchmark target

This benchmark target needs IB support.