[POWERPC] Create modalias file in sysfs for of_platform bus

Create /sys/bus/of_platform/devices/*/modalias file to allow autoloading
of modules.  Modalias files are already present for many other bus types.
This adds also a newline to the devspec files.

Also create a devspec file for mac-io devices.  They were created as a
side effect.  Use correct buffer size for mac-io modalias buffer.

Tested on iBook1 and Efika.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/drivers/macintosh/macio_sysfs.c b/drivers/macintosh/macio_sysfs.c
index 112e5ef..9e9453b 100644
--- a/drivers/macintosh/macio_sysfs.c
+++ b/drivers/macintosh/macio_sysfs.c
@@ -44,7 +44,7 @@
 	struct of_device *ofdev = to_of_device(dev);
 	int len;
 
-	len = of_device_get_modalias(ofdev, buf, PAGE_SIZE);
+	len = of_device_get_modalias(ofdev, buf, PAGE_SIZE - 2);
 
 	buf[len] = '\n';
 	buf[len+1] = 0;
@@ -52,6 +52,15 @@
 	return len+1;
 }
 
+static ssize_t devspec_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct of_device *ofdev;
+
+	ofdev = to_of_device(dev);
+	return sprintf(buf, "%s\n", ofdev->node->full_name);
+}
+
 macio_config_of_attr (name, "%s\n");
 macio_config_of_attr (type, "%s\n");
 
@@ -60,5 +69,6 @@
 	__ATTR_RO(type),
 	__ATTR_RO(compatible),
 	__ATTR_RO(modalias),
+	__ATTR_RO(devspec),
 	__ATTR_NULL
 };