clk: tegra: Do not warn unnecessarily

There is no need to warn if the reference PLL is enabled with the
correct defaults. Only warn if the boot values don't match the defaults.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>