mfd: Correct revision display for WM1811 revision D

As WM1811 revision C was transparent to software the revision IDs for
subsequent revisions are one less than they would normally be. Correct
for this in log messages.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NSamuel Ortiz <sameo@linux.intel.com>

drivers/mfd/wm8994-core.c

@@ -460,6 +460,11 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 			break;
 		}
 		break;
+	case WM1811:
+		/* Revision C did not change the relevant layer */
+		if (ret > 1)
+			ret++;
+		break;
 	default:
 		break;
 	}