dmaengine: dw-axi-dmac: Simplify assignment in dma_chan_pause()

Simplify assigning zero and performing a logical OR to a single
assignment.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/2abd0da35608c14689a919d47dd45898a8ab4297.1635263478.git.geert@linux-m68k.org


Signed-off-by: Vinod Koul <vkoul@kernel.org>