net/davinci_cpdma: remove unused argument in cpdma_chan_submit()

The gfp_mask argument is not used in cpdma_chan_submit() and always set
to GFP_KERNEL even in atomic sections. This patch drops it since it is
unused.

Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>