mfd: twl4030-irq: Fix incorrect type in assignment warning

Silences Sparse warning:

 drivers/mfd/twl4030-irq.c:485:26: warning: incorrect type in assignment (different base types)
 drivers/mfd/twl4030-irq.c:485:26:    expected unsigned int [usertype] word
 drivers/mfd/twl4030-irq.c:485:26:    got restricted __le32 [usertype]

Cc: Tony Lindgren <tony@atomide.com>
Cc: Kai Svahn <kai.svahn@nokia.com>
Cc: Syed Khasim <x0khasim@ti.com>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/twl4030-irq.c

@@ -477,7 +477,7 @@ static void twl4030_sih_bus_sync_unlock(struct irq_data *data)
 
 	if (agent->imr_change_pending) {
 		union {
-			u32	word;
+			__le32	word;
 			u8	bytes[4];
 		} imr;