drm/nouveau/clk/gk20a: reorganize variables in gk20a_pllg_calc_mnp()

Move some variables declarations to the scope where they are actually
used to make the code easier to follow.

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