linux-imx

spi: imx: drop unncessary dma_is_inited variable

There's no need for an extra dma_is_inited variable when we can
equally well check for the existence of a DMA channel.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>