spi: update the structure documentation

some members were not described in documentation.
Signed-off-by: NQiujun Huang <hqjagain@gmail.com>
Link: https://lore.kernel.org/r/1583774179-30736-1-git-send-email-hqjagain@gmail.comSigned-off-by: NMark Brown <broonie@kernel.org>

include/linux/spi/spi.h

@@ -135,6 +135,8 @@ extern int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer);
  * @modalias: Name of the driver to use with this device, or an alias
  *	for that name.  This appears in the sysfs "modalias" attribute
  *	for driver coldplugging, and in uevents used for hotplugging
+ * @driver_override: If the name of a driver is written to this attribute, then
+ *	the device will bind to the named driver and only the named driver.
  * @cs_gpio: LEGACY: gpio number of the chipselect line (optional, -ENOENT when
  *	not using a GPIO line) use cs_gpiod in new drivers by opting in on
  *	the spi_master.
@@ -443,6 +445,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  *	@spi_transfer->ptp_sts_word_post were transmitted.
  *	If the driver does not set this, the SPI core takes the snapshot as
  *	close to the driver hand-over as possible.
+ * @irq_flags: Interrupt enable state during PTP system timestamping
  *
  * Each SPI controller can communicate with one or more @spi_device
  * children.  These make a small bus, sharing MOSI, MISO and SCK signals