Some devices don't use mmio to interact with dividers. Split out the
logic from the register read/write parts so that we can reuse the
division logic elsewhere.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Tested-by: NKenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>