clk: axi-clkgen: Set power bits for fractional mode

clk: axi-clkgen: Set power bits for fractional mode

Using the fractional dividers requires some additional power bits to be
set.

The fractional power bits are not documented and the current heuristic
for setting them seems be insufficient for some cases. Just always set all
the fractional power bits when in fractional mode.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201001085948.21412-2-alexandru.ardelean@analog.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>