media: omap3isp.h: fix kernel-doc warnings

Add missing documentation for two field. This fixes these kernel-doc
warnings:

drivers/media/platform/omap3isp/omap3isp.h:107: warning: Function parameter or member 'vp_clk_pol' not described in 'isp_ccp2_cfg'
drivers/media/platform/omap3isp/omap3isp.h:107: warning: Function parameter or member 'lanecfg' not described in 'isp_ccp2_cfg'

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>