[POWERPC] bootwrapper: Add find_node_by_compatible

Add the ability to find a device node by just what its compatible with.
This is useful in cases that we don't have a prop to find the node with.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/boot/ops.h

@@ -46,6 +46,8 @@ struct dt_ops {
 	void *(*find_node_by_prop_value)(const void *prev,
 	                                 const char *propname,
 	                                 const char *propval, int proplen);
+	void *(*find_node_by_compatible)(const void *prev,
+	                                 const char *compat);
 	unsigned long (*finalize)(void);
 	char *(*get_path)(const void *phandle, char *buf, int len);
 };
@@ -172,6 +174,15 @@ static inline void *find_node_by_alias(const char *alias)
 	return NULL;
 }
 
+static inline void *find_node_by_compatible(const void *prev,
+                                            const char *compat)
+{
+	if (dt_ops.find_node_by_compatible)
+		return dt_ops.find_node_by_compatible(prev, compat);
+
+	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);