drm/nouveau/clk/gk20a: add and use MNP programming functions

Add relevant functions to work with the gk20a_pll structure and use them
where they ought to be instead of directly manipulating registers.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
1 file changed