spi: dw-mmio: add ACPI support

The Hisilicon Hip08 platform, that uses ACPI, has this controller.
Let's add ACPI support for DW SPI MMIO-based host.

The ACPI ID used is "HISI0173" for the Designware SPI controller of
Hisilicon Hip08 platform.

Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index b705f2b..2e822a5 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -507,6 +507,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
 	master->handle_err = dw_spi_handle_err;
 	master->max_speed_hz = dws->max_freq;
 	master->dev.of_node = dev->of_node;
+	master->dev.fwnode = dev->fwnode;
 	master->flags = SPI_MASTER_GPIO_SS;
 
 	if (dws->set_cs)