[POWERPC] Export of_device_get_modalias

Apparently other parts of the kernel need to know the
modalias internally (like the sysfs code in macintosh driver).

To avoid consistency issues, we export this code and use it
everywhere it's needed rather than repeat it ...

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/of_device.h b/include/asm-powerpc/of_device.h
index 4f1aabe..e9af49e 100644
--- a/include/asm-powerpc/of_device.h
+++ b/include/asm-powerpc/of_device.h
@@ -32,6 +32,8 @@
 extern void of_device_unregister(struct of_device *ofdev);
 extern void of_release_dev(struct device *dev);
 
+extern ssize_t of_device_get_modalias(struct of_device *ofdev,
+					char *str, ssize_t len);
 extern int of_device_uevent(struct device *dev,
 	char **envp, int num_envp, char *buffer, int buffer_size);