media: ti-vpe: cal: Rename cal_ctx.csi2_port to cal_ctx.index

media: ti-vpe: cal: Rename cal_ctx.csi2_port to cal_ctx.index

The csi2_port field of the cal_ctx structure holds the context index,
and is independent from the CSI-2 port (even if it currently has the
same numerical value). Rename it to index to avoid the ambiguity.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>