dvfs: tegra: Update error codes.

dvfs: tegra: Update error codes.

- Returned -ENODATA error from voltage predict interfaces called on
  clock with no DVFS (instead of 0 mV).

- Returned -ENODATA error from DVFS voltage set interfaces called on
  clock with no DVFS (instead of -EINVAL).

- Returned -EINVAL error from voltage and frequency predict/get
  interfaces called on clock with alternative DVFS frequencies
  (instead of -ENOSYS).

Change-Id: I32d79e106825963b9bfa78215f1d974c7b681a60
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/723819
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>