dmaengine/ste_dma40: make the cyclic alloc NOWAIT

This function may be initiated from IRQ context, so the allocation
must allocate NOWAIT memory.

Signed-off-by: Robert Marklund <robert.marklund@stericsson.com>
Reviewed-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Philippe Langlais <philippe.langlais@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>