mpll clocks parent can actually be divided by 1 or 2. So far, this
divider has always been set to 1, so the calculation was correct.
Now that we know it exists, model the tree correctly. If we ever get
a platform where the divider is different, we won't get into trouble
Signed-off-by: NJerome Brunet <jbrunet@baylibre.com>
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>