According to the datasheet, it is not allowed to change div4 clock rates
if an earlier rate change operation is still in progress, as indicated by
a set kick bit.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>