clk: tegra: move some PLLC and PLLXC init to clk-pll.c

VCO min clipping, dynamic ramp setup and IDDQ init can be done in the
respective PLL clk_register functions if the parent is already registered.
This is done for other some PLLs already.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>