arm: mvebu: turris_mox: Setup Linux's device tree before boot

Patch Linux's device tree according to which Mox modules are connected.
Linux's device tree has all possible Mox module nodes preprogrammed, but
in disabled state.

If MOX B, MOX F or MOX G module is present, this code enables the PCI
node.

For the network modules (MOX C, MOX D and MOX E) are present, the code
enables corresponding ethernet and swtich nodes and DSA connections.
For the SFP cage the SFP GPIO controller node and SFP node are also
enabled.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>