radeon-gallium: Add my R580 to the xorg PCI ID list.

At some point, going to have to grab the big list from xf86-video-ati.

src/gallium/winsys/drm/radeon/xorg/radeon_xorg.c

@@ -39,16 +39,19 @@ static Bool radeon_xorg_pci_probe(DriverPtr driver,
 
 static const struct pci_id_match radeon_xorg_device_match[] = {
     {0x1002, 0x5E4D, 0xffff, 0xffff, 0, 0, 0},
+    {0x1002, 0x7249, 0xffff, 0xffff, 0, 0, 0},
     {0, 0, 0},
 };
 
 static SymTabRec radeon_xorg_chipsets[] = {
     {0x5E4D, "Radeon RV410 PCIE (X700)"},
+    {0x7249, "Radeon R580 PCIE (X1900 XT)"},
     {-1, NULL}
 };
 
 static PciChipsets radeon_xorg_pci_devices[] = {
     {0x5E4D, 0x5E4D, RES_SHARED_VGA},
+    {0x7249, 0x7249, RES_SHARED_VGA},
     {-1, -1, RES_UNDEFINED}
 };