mfd: si476x-core.h: Fix "regulator" spelling in comment

"regualtor" -> "regulator"
Signed-off-by: Michael Klein <michael@fossekall.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

include/linux/mfd/si476x-core.h

@@ -57,7 +57,7 @@ enum si476x_mfd_cells {
  * @SI476X_POWER_DOWN: In this state all regulators are turned off
  * and the reset line is pulled low. The device is completely
  * inactive.
- * @SI476X_POWER_UP_FULL: In this state all the power regualtors are
+ * @SI476X_POWER_UP_FULL: In this state all the power regulators are
  * turned on, reset line pulled high, IRQ line is enabled(polling is
  * active for polling use scenario) and device is turned on with
  * POWER_UP command. The device is ready to be used.