Split the VC5 clock input mux and the predivider to more accurately
model the hardware and fix the previously incorrect assumption that
both the OUT_SEL_I2CB and the PLL are fed from the predivider.

It is in fact the clock input mux output which is directly feeding
the clock into the OUT_SEL_I2CB output, while the clock input mux
output first passes through the predivider before it is fed into
the PLL.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Alexey Firago <alexey_firago@mentor.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: linux-renesas-soc@vger.kernel.org
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
on Salvator-XS with the display LVDS output.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>