Adding Mellanox manifests for mellanox plugin

1. iSER configuration on cinder node.
2. Installing and configuring Mellanox plugin on compute node.

partially implements: blueprint mellanox-features-support

Change-Id: I207f7d884eeb2f063e90deb99459f546c116607c
Signed-off-by: gilmeir <gilmeir@mellanox.com>
Merge "Adding Mellanox manifests for mellanox plugin"