COMPMID-765 - Call graph_init only once all nodes have been instantied

- In order to enable to OpenCL tuner, graph_init() has to be called only
  once all nodes have been instantiated

Change-Id: I28a51ccada8f81c12e4f4484b892f14a530f6f4d
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/121707
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Tested-by: Jenkins <bsgcomp@arm.com>
11 files changed