dma/imx-sdma: convernt to use bit ops

We don't need extra lock, so we use non-atomic bit ops to set/clear bits,

merge event_mask0 and event_mask1 into an array, it helps use bit ops.

It also fixs the issue:

sdmac->event_mask0 = 1 << sdmac->event_id0;
sdmac->event_mask1 = 1 << (sdmac->event_id0 - 32);

It event_id0 < 32, it shifts negative number. If event_id0 >= 32, it
shifts number >= sizeof(int). Both the cases behavior is undefined.

Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>