powerpc/powernv: Create platform devs for nvdimm buses

Scan the devicetree for an nvdimm-bus compatible and create
a platform device for them.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

arch/powerpc/platforms/powernv/opal.c

@@ -821,6 +821,9 @@ static int __init opal_init(void)
 	/* Create i2c platform devices */
 	opal_pdev_init("ibm,opal-i2c");
 
+	/* Handle non-volatile memory devices */
+	opal_pdev_init("pmem-region");
+
 	/* Setup a heatbeat thread if requested by OPAL */
 	opal_init_heartbeat();