drm/bridge: Constify struct i2c_device_id

'struct i2c_device_id' is not modified in these drivers.

Constifying this structure moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  15566	    987	     32	  16585	   40c9	drivers/gpu/drm/bridge/chipone-icn6211.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  15630	    923	     32	  16585	   40c9	drivers/gpu/drm/bridge/chipone-icn6211.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/bdba1f49b4b48e22628482b49ce81f8e1f0d97b1.1731445901.git.christophe.jaillet@wanadoo.fr