wireless: Print wiphy name in sysfs.

The index cannot be used to reliably reconstruct a phy
name, so explicitly add the phy name to sysfs so that scripts
can figure out the parent phy device for a particular
wireless interface.

Signed-off-by: Ben Greear <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

net/wireless/sysfs.c

···
 SHOW_FMT(macaddress, "%pM", wiphy.perm_addr);
 SHOW_FMT(address_mask, "%pM", wiphy.addr_mask);
 
+static ssize_t name_show(struct device *dev,
+			 struct device_attribute *attr,
+			 char *buf) {
+	struct wiphy *wiphy = &dev_to_rdev(dev)->wiphy;
+	return sprintf(buf, "%s\n", dev_name(&wiphy->dev));
+}
+
+
 static ssize_t addresses_show(struct device *dev,
 			      struct device_attribute *attr,
 			      char *buf)
···
 	__ATTR_RO(macaddress),
 	__ATTR_RO(address_mask),
 	__ATTR_RO(addresses),
+	__ATTR_RO(name),
 	{}
 };