radeon_hd: Polaris10 power distribution fix

* Helps prevent mainboard explosions and other bad stuff.
* ...maybe not explosions, but bad things.
* The RX 480 reference design can pull as much as 90W
  from its PCIe slot at load. PCIe is rated for 75W.
* This change overloads the PCIe power cables vs the PCIe
  slot. The PCIe power cables can handle going over spec.
* Untested since we really can't come close to loading a
  RX 480 without hardware OpenGL ^_^
* Should be able to test on real hardware within a week.

headers/private/graphics/radeon_hd/radeon_hd.h

@@ -190,7 +190,8 @@ struct overlay_registers;
 
 struct radeon_shared_info {
 	uint32			deviceIndex;		// accelerant index
-	uint32			pciID;				// device pciid
+	uint32			pciID;				// device pci id
+	uint32			pciRev;				// device pci revision
 	area_id			mode_list_area;		// area containing display mode list
 	uint32			mode_count;