regulator: twl-regulator - fix twlreg_set_mode

The Singular Message is 16 bits:
        DEV_GRP[15:13] MT[12]  RES_ID[11:4]  RES_STATE[3:0]

Current implementation return immedially after sucessfuly write MSB part.
To properly set mode, we need to write the complete message ( MSB and LSB ).

In twl.h, now we have defines for PM Master module register offsets,
use it instead of hard coded 0x15/0x16.

Use "message & 0xff" to ensure we send correct value for LSB.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Tested-by: Lesly Arackal Manuel <leslyam@ti.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

drivers/regulator/twl-regulator.c

@@ -219,12 +219,12 @@ static int twlreg_set_mode(struct regulator_dev *rdev, unsigned mode)
 		return -EACCES;
 
 	status = twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
-			message >> 8, 0x15 /* PB_WORD_MSB */ );
-	if (status >= 0)
+			message >> 8, TWL4030_PM_MASTER_PB_WORD_MSB);
+	if (status < 0)
 		return status;
 
 	return twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
-			message, 0x16 /* PB_WORD_LSB */ );
+			message & 0xff, TWL4030_PM_MASTER_PB_WORD_LSB);
 }
 
 /*----------------------------------------------------------------------*/