spi: spidev: add SPI_RX_CPHA_FLIP

Allow userspace to set SPI_RX_CPHA_FLIP mode bit using the
SPI_IOC_WR_MODE32 ioctl.

Signed-off-by: Baruch Siach <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spidev.c

···
 				| SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \
 				| SPI_NO_CS | SPI_READY | SPI_TX_DUAL \
 				| SPI_TX_QUAD | SPI_TX_OCTAL | SPI_RX_DUAL \
-				| SPI_RX_QUAD | SPI_RX_OCTAL)
+				| SPI_RX_QUAD | SPI_RX_OCTAL \
+				| SPI_RX_CPHA_FLIP)
 
 struct spidev_data {
 	dev_t			devt;