media: ov5640: Correct Bit Div register in clock tree diagram

Although the code is correct and doing the right thing, the clock diagram
showed the wrong register for the bit divider, which had me doubting the
understanding of the tree. Fix this to avoid doubts in the future.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Fixes: aa288248 ("media: ov5640: Adjust the clock based on the expected rate")
Acked-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>