rtlwifi: Align private space in rtl_priv struct

The private array at the end of the rtl_priv struct is not aligned.
On ARM architecture, this causes an alignment trap and is fixed by aligning
that array with __align(sizeof(void *)). That should properly align that
space according to the requirements of all architectures.
Reported-by: Jason Andrews <jasona@cadence.com>
Tested-by: Jason Andrews <jasona@cadence.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rtlwifi/wifi.h

@@ -2057,7 +2057,7 @@ struct rtl_priv {
 	   that it points to the data allocated
 	   beyond  this structure like:
 	   rtl_pci_priv or rtl_usb_priv */
-	u8 priv[0];
+	u8 priv[0] __aligned(sizeof(void *));
 };
 
 #define rtl_priv(hw)		(((struct rtl_priv *)(hw)->priv))