regulator: rk808: Return REGULATOR_MODE_INVALID for invalid mode

-EINVAL is not a valid return value for .of_map_mode, return
REGULATOR_MODE_INVALID instead.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20190711122138.5221-1-axel.lin@ingics.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/rk808-regulator.c

@@ -606,7 +606,7 @@ static unsigned int rk8xx_regulator_of_map_mode(unsigned int mode)
 	case 2:
 		return REGULATOR_MODE_NORMAL;
 	default:
-		return -EINVAL;
+		return REGULATOR_MODE_INVALID;
 	}
 }