fakehard: stop setting platform_data as it's unused anymore

Previously dev.platform_data was used to store a pointer to net device.
Now this code was gone. Drop it.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
diff --git a/drivers/ieee802154/fakehard.c b/drivers/ieee802154/fakehard.c
index a5a49a1..eb0e2cc 100644
--- a/drivers/ieee802154/fakehard.c
+++ b/drivers/ieee802154/fakehard.c
@@ -370,8 +370,6 @@
 		return -ENOMEM;
 	}
 
-	phy->dev.platform_data = dev;
-
 	memcpy(dev->dev_addr, "\xba\xbe\xca\xfe\xde\xad\xbe\xef",
 			dev->addr_len);
 	memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);