gpu: nvgpu: Combine delays with GM20B parameters

gpu: nvgpu: Combine delays with GM20B parameters

Added delays definitions to GPCPLL parameters structure:
- locking timeout delay (applied to locking in fixed frequency mode and
  to PLL dynamic ramp in any mode)
- lock delay for GPCPLL NA mode
- IDDQ exit delay in any mode

Specified delay parameters for GM20B PLL, and used this data instead of
hard-coded numbers.

Change-Id: I63ce0abc9ee900c36ec34b8641513db3cbb6f7d5
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/732094
Reviewed-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>