clk: tegra: Fix T210 effective NDIV calculation

Don't take the fractional part into account to calculate the effective
NDIV if fractional ndiv is not enabled.

Signed-off-by: Alex Frid <afrid@nvidia.com>
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>