If SPI device supports DMA mode, but DMA controller is not yet
available due to e.g. a delay in the corresponding kernel module
initialization, retry to initialize SPI driver later on instead of
falling back into PIO only mode.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>