dmaengine: coh901318: use NULL for pointer initialization

Sparse complains:
drivers/dma/coh901318_lli.c:78:31: warning: Using plain integer as NULL pointer
drivers/dma/coh901318_lli.c:91:39: warning: Using plain integer as NULL pointer

Use NULL for pointer initialization rather than plain integer

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
1 file changed