dmaengine: iop-adma: Function parameter documentation must adhere to correct formatting

Also remove superfluous entry.

Fixes the following W=1 kernel build warning(s):

 drivers/dma/iop-adma.c:418: warning: Function parameter or member 'chan' not described in 'iop_adma_alloc_chan_resources'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200714111546.1755231-13-lee.jones@linaro.org


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