spi: flags 'SPI_CONTROLLER_MUST_RX' and 'SPI_CONTROLLER_MUST_TX' can't be coexit...

spi: flags 'SPI_CONTROLLER_MUST_RX' and 'SPI_CONTROLLER_MUST_TX' can't be coexit with 'SPI_3WIRE' mode

since chip spi driver need get the transfer direction by 'tx_buf' and
'rx_buf' of 'struct spi_transfer' in 'SPI_3WIRE' mode.

so, we need bypass 'SPI_CONTROLLER_MUST_RX' and 'SPI_CONTROLLER_MUST_TX'
feature in 'SPI_3WIRE' mode

Signed-off-by: dillon min <dillon.minfei@gmail.com>
Link: https://lore.kernel.org/r/1590378348-8115-9-git-send-email-dillon.minfei@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>