staging: media: tegra-video: move tegra210_csi_soc declaration to csi.h

staging: media: tegra-video: move tegra210_csi_soc declaration to csi.h

Sparse warns that tegra210_csi_soc is not declared in tegra210.c.
The symbol is referenced from csi.c, so it must remain global. Move the
declaration to csi.h so users see it via the header and avoid extern
declarations in .c files.

SPARSE: drivers/staging/media/tegra-video/tegra210.c:1214:28: warning:
 symbol 'tegra210_csi_soc' was not declared. Should it be static?

No functional change intended.

Suggested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>