dmaengine: imx-dma: fix coding style issue

imxdma_probe function starting brace is wrongly indented, so fix that

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>