dt-bindings: dma: fsl-edma: Add fsl-edma.h to prevent hardcoding in dts

Introduce a common dt-bindings header file, fsl-edma.h, shared between
the driver and dts files. This addition aims to eliminate hardcoded values
in dts files, promoting maintainability and consistency.

DTS header file not support BIT() macro yet. Directly use 2^n number.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231114154824.3617255-3-Frank.Li@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>