media: tegra-video/csi.h: fix kernel-doc mistake

Fixes this kernel-doc warning:

drivers/staging/media/tegra-video/csi.h:152: warning: Function parameter or member 'csi_chans' not described in 'tegra_csi'

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>