dmaengine: ioat: Fix some parameter misspelling and provide description for phys_complete

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

 drivers/dma/ioat/dma.c:202: warning: Function parameter or member 'ioat_chan' not described in 'ioat_update_pending'
 drivers/dma/ioat/dma.c:202: warning: Excess function parameter 'ioat' description in 'ioat_update_pending'
 drivers/dma/ioat/dma.c:465: warning: Function parameter or member 'ioat_chan' not described in 'ioat_check_space_lock'
 drivers/dma/ioat/dma.c:465: warning: Excess function parameter 'ioat' description in 'ioat_check_space_lock'
 drivers/dma/ioat/dma.c:591: warning: Function parameter or member 'ioat_chan' not described in '__cleanup'
 drivers/dma/ioat/dma.c:591: warning: Function parameter or member 'phys_complete' not described in '__cleanup'
 drivers/dma/ioat/dma.c:591: warning: Excess function parameter 'ioat' description in '__cleanup'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Leonid Ravich <Leonid.Ravich@emc.com>
Link: https://lore.kernel.org/r/20200714111546.1755231-18-lee.jones@linaro.org


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