nb/intel/sandybridge: Do not hardcode resource indices

Other northbridges use an index variable to assign monotonically
incrementing values to each resource. Do it here as well.

Change-Id: I8719a1a5973a10531cf11b3307652212cb3d4895
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41375
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/northbridge/intel/sandybridge/northbridge.c b/src/northbridge/intel/sandybridge/northbridge.c
index c1cdea5..ce28c05 100644
--- a/src/northbridge/intel/sandybridge/northbridge.c
+++ b/src/northbridge/intel/sandybridge/northbridge.c
@@ -135,6 +135,7 @@
 	uint32_t tseg_base, uma_size, tolud;
 	uint16_t ggc;
 	unsigned long long tomk;
+	unsigned long index = 3;
 
 	pci_dev_read_resources(dev);
 
@@ -238,9 +239,9 @@
 	printk(BIOS_INFO, "Available memory below 4GB: %lluM\n", tomk >> 10);
 
 	/* Report the memory regions */
-	ram_resource(dev, 3, 0, legacy_hole_base_k);
-	ram_resource(dev, 4, legacy_hole_base_k + legacy_hole_size_k,
-		    (tomk - (legacy_hole_base_k + legacy_hole_size_k)));
+	ram_resource(dev, index++, 0, legacy_hole_base_k);
+	ram_resource(dev, index++, legacy_hole_base_k + legacy_hole_size_k,
+			  (tomk - (legacy_hole_base_k + legacy_hole_size_k)));
 
 	/*
 	 * If >= 4GB installed, then memory from TOLUD to 4GB is remapped above TOM.
@@ -248,11 +249,11 @@
 	 */
 	touud >>= 10; /* Convert to KB */
 	if (touud > 4096 * 1024) {
-		ram_resource(dev, 5, 4096 * 1024, touud - (4096 * 1024));
+		ram_resource(dev, index++, 4096 * 1024, touud - (4096 * 1024));
 		printk(BIOS_INFO, "Available memory above 4GB: %lluM\n", (touud >> 10) - 4096);
 	}
 
-	add_fixed_resources(dev, 6);
+	add_fixed_resources(dev, index++);
 }
 
 static void northbridge_dmi_init(struct device *dev)