[POWERPC] bootwrapper: Add find_node_by_alias and dt_fixup_mac_address_by_alias

Add the ability to set the mac address given the alias for the device.
Removes the need for having a linux,network-index property.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h
index 6036a98..5872ef1 100644
--- a/arch/powerpc/boot/ops.h
+++ b/arch/powerpc/boot/ops.h
@@ -159,9 +159,23 @@
 	return find_node_by_prop_value_str(prev, "device_type", type);
 }
 
+static inline void *find_node_by_alias(const char *alias)
+{
+	void *devp = finddevice("/aliases");
+
+	if (devp) {
+		char path[MAX_PATH_LEN];
+		if (getprop(devp, alias, path, MAX_PATH_LEN) > 0)
+			return finddevice(path);
+	}
+
+	return NULL;
+}
+
 void dt_fixup_memory(u64 start, u64 size);
 void dt_fixup_cpu_clocks(u32 cpufreq, u32 tbfreq, u32 busfreq);
 void dt_fixup_clock(const char *path, u32 freq);
+void dt_fixup_mac_address_by_alias(const char *alias, const u8 *addr);
 void dt_fixup_mac_address(u32 index, const u8 *addr);
 void __dt_fixup_mac_addresses(u32 startindex, ...);
 #define dt_fixup_mac_addresses(...) \