spi: sirf: assign spi_master's max_speed_hz member

if spi device has no frequency, spi core will setup the default frequency
to max_speed_hz of spi_master according to
int spi_setup(struct spi_device *spi)
{
	...
        if (!spi->max_speed_hz)
                spi->max_speed_hz = spi->master->max_speed_hz;
	...
}
this patch moves CSR SiRFSoC SPI frequency set to follow SPI core behaviour.
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-sirf.c

@@ -134,6 +134,7 @@
 	ALIGNED(x->len) && (x->len < 2 * PAGE_SIZE))
 
 #define SIRFSOC_MAX_CMD_BYTES	4
+#define SIRFSOC_SPI_DEFAULT_FRQ 1000000
 
 struct sirfsoc_spi {
 	struct spi_bitbang bitbang;
@@ -629,9 +630,6 @@ static int spi_sirfsoc_setup(struct spi_device *spi)
 {
 	struct sirfsoc_spi *sspi;
 
-	if (!spi->max_speed_hz)
-		return -EINVAL;
-
 	sspi = spi_master_get_devdata(spi->master);
 
 	if (spi->cs_gpio == -ENOENT)
@@ -683,6 +681,7 @@ static int spi_sirfsoc_probe(struct platform_device *pdev)
 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_CS_HIGH;
 	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(12) |
 					SPI_BPW_MASK(16) | SPI_BPW_MASK(32);
+	master->max_speed_hz = SIRFSOC_SPI_DEFAULT_FRQ;
 	sspi->bitbang.master->dev.of_node = pdev->dev.of_node;
 
 	/* request DMA channels */