firewire: ohci: use helper macro for compiler aligned attribute

The __aligned() macro has been available since v4.19 kernel by a commit
815f0dd ("include/linux/compiler*.h: make compiler-*.h mutually
exclusive").

This commit replaces with the macro.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Sakamoto <[email protected]>

Author: takaswie

drivers/firewire/ohci.c

@@ -77,7 +77,7 @@ struct descriptor {
 	__le32 branch_address;
 	__le16 res_count;
 	__le16 transfer_status;
-} __attribute__((aligned(16)));
+} __aligned(16);
 
 #define CONTROL_SET(regs)	(regs)
 #define CONTROL_CLEAR(regs)	((regs) + 4)