mfd: ti_am335x_tscadc: Use PLATFORM_DEVID_AUTO while registering mfd cells

Use PLATFORM_DEVID_AUTO to number mfd cells while registering, so that
different instances are uniquely identified. This is required in order
to support registering of multiple instances of same ti_am335x_tscadc IP.

Signed-off-by: Vignesh R <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/ti_am335x_tscadc.c

···
 		cell->pdata_size = sizeof(tscadc);
 	}
 
-	err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
-			tscadc->used_cells, NULL, 0, NULL);
+	err = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
+			      tscadc->cells, tscadc->used_cells, NULL,
+			      0, NULL);
 	if (err < 0)
 		goto err_disable_clk;