g80/output: update known PCI rom sigs

See src/common/nvswitch/kernel/inc/rom_nvswitch.h in open-gpu-kernel-modules

Signed-off-by: Yusuf Khan <yusisamerican@gmail.com>
Part-of: <https://gitlab.freedesktop.org/xorg/driver/xf86-video-nv/-/merge_requests/16>

src/g80_output.c

@@ -79,7 +79,15 @@ static Bool G80ReadPortMapping(int scrnIndex, G80Ptr pNv)
     for(i = 0; i < G80_NUM_I2C_PORTS; i++)
         pNv->i2cMap[i].dac = pNv->i2cMap[i].sor = -1;
 
-    if(*(CARD16*)pNv->table1 != 0xaa55) goto fail;
+    /* These are the three possible known rom signatures */
+    switch(*(CARD16*)pNv->table1) {
+        case 0xaa55:
+        case 0x4e56:
+        case 0xbb77:
+            break;
+        default:
+            goto fail;
+    }
 
     a = *(CARD16*)(pNv->table1 + 0x36);
     table2 = (unsigned char*)pNv->table1 + a;