mfd: Don't hard code the reset value for WM8994 devices

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
index c8956f2c..0167694 100644
--- a/drivers/mfd/wm8994-core.c
+++ b/drivers/mfd/wm8994-core.c
@@ -276,7 +276,8 @@
 	/* Explicitly put the device into reset in case regulators
 	 * don't get disabled in order to ensure consistent restart.
 	 */
-	wm8994_reg_write(wm8994, WM8994_SOFTWARE_RESET, 0x8994);
+	wm8994_reg_write(wm8994, WM8994_SOFTWARE_RESET,
+			 wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET));
 
 	wm8994->suspended = true;