spi: rockchip: add missing spi_master_put

Add missing spi_master_put for rockchip_spi_remove since
it calls spi_master_get already.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-rockchip.c

@@ -779,6 +779,8 @@ static int rockchip_spi_remove(struct platform_device *pdev)
 	if (rs->dma_rx.ch)
 		dma_release_channel(rs->dma_rx.ch);
 
+	spi_master_put(master);
+
 	return 0;
 }