spi: add SPI_RX_CPHA_FLIP mode bit

Some SPI devices latch MOSI bits on one clock phase, but produce valid
MISO bits on the other phase. Add SPI_RX_CPHA_FLIP mode to instruct the
controller driver to flip CPHA for Rx (MISO) only transfers.
Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
Link: https://lore.kernel.org/r/a715ca92713ca02071f33dcca9960a66a03c949a.1649702729.git.baruch@tkos.co.ilSigned-off-by: Mark Brown <broonie@kernel.org>

include/uapi/linux/spi/spi.h

@@ -27,6 +27,7 @@
 #define	SPI_TX_OCTAL		_BITUL(13)	/* transmit with 8 wires */
 #define	SPI_RX_OCTAL		_BITUL(14)	/* receive with 8 wires */
 #define	SPI_3WIRE_HIZ		_BITUL(15)	/* high impedance turnaround */
+#define	SPI_RX_CPHA_FLIP	_BITUL(16)	/* flip CPHA on Rx only xfer */
 
 /*
  * All the bits defined above should be covered by SPI_MODE_USER_MASK.
@@ -36,6 +37,6 @@
  * These bits must not overlap. A static assert check should make sure of that.
  * If adding extra bits, make sure to increase the bit index below as well.
  */
-#define SPI_MODE_USER_MASK	(_BITUL(16) - 1)
+#define SPI_MODE_USER_MASK	(_BITUL(17) - 1)
 
 #endif /* _UAPI_SPI_H */