media: sun6i-csi: Rename sun6i_video to sun6i_csi_capture

In an effort to distinguish between the core csi engine (to be
represented as the bridge) and the dma engine (the capture video
device), rename the video component to capture, with the appropriate
prefix. No functional change intended.

[Sakari Ailus: fix wrong variable issue (video -> capture) missed in patch]

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>