Upstream commit d40f0b6f2e21 ("spi: Avoid settingthe chip select if
we don't need to") causes the SPI CS only to be asserted once and not
if it's state stays the same.

This seems to cause problems with the SPI on the AR724x and the AR913x
(but not the AR71xx). AR934x and subsequent chips do not look affected.

ToDo:
 - Analyze if this is a hardware bug or a bug in the software.
 - Send a cleaned up patch upstream.

Signed-off-by: David Bauer <mail@david-bauer.net>

--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -791,6 +791,7 @@ static void spi_set_cs(struct spi_device
 {
 	bool enable1 = enable;
 
+#if 0
 	/*
 	 * Avoid calling into the driver (or doing delays) if the chip select
 	 * isn't actually changing from the last time this was called.
@@ -801,6 +802,7 @@ static void spi_set_cs(struct spi_device
 
 	spi->controller->last_cs_enable = enable;
 	spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
+#endif
 
 	if (!spi->controller->set_cs_timing) {
 		if (enable1)