media: rcar-csi2: Drop comma after SoC match table sentinel

It does not make sense to have a comma after a sentinel, as any new
elements must be added before the sentinel.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>