spi: always use software fallback for SPI_CS_WORD when using cs_gio

This modifies the condition for using the software fallback
implementation for SPI_CS_WORD when the SPI controller is using a GPIO
for the CS line. When using a GPIO for CS, the hardware implementation
won't work, so we just enable the software fallback globally in this
case.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Mark Brown <broonie@kernel.org>