spi: imx: fallback to PIO if dma setup failure

Fallback to PIO in case dma setup failed. For example, sdma firmware not
updated but ERR009165 workaroud added in kernel.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/1590006865-20900-6-git-send-email-yibin.gong@nxp.com


Signed-off-by: Mark Brown <broonie@kernel.org>