clk: tegra: Enable hardware control of PLLE

Enable hardware control of PLLE spread-spectrum, IDDQ, and enable
controls when enabling PLLE.  The hardware (e.g. XUSB) using PLLE
will use these controls for power-saving optimizations.

Signed-off-by: Jim Lin <jilin@nvidia.com>
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>