spi: let SPI masters ignore their children for PM

Let all SPI masters ignore their children: when it comes
to power management: SPI children have no business doing
keeping their parents awake: they are completely autonomous
devices that just use their parent to talk, and the latter
usecase must be power managed by the host itself on a
per-message basis.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

drivers/spi/spi.c

@@ -1764,6 +1764,7 @@ struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
 	master->num_chipselect = 1;
 	master->dev.class = &spi_master_class;
 	master->dev.parent = dev;
+	pm_suspend_ignore_children(&master->dev, true);
 	spi_master_set_devdata(master, &master[1]);
 
 	return master;