v2: remove check for error during swsmu amdgpu_dpm_get_pp_num_states() call to match previous powerplay behaviour
v3: removed smu implementation of powerplay get_power_limit
    Resolved context clashes with other commits

Modified Files
  smu_set_power_limit()         - modifed arg0 to match Powerplay API set_power_limit
  smu_sys_get_pp_table()        - modifed signature to match Powerplay API get_pp_table
  smu_get_power_num_states()    - modifed arg0 to match Powerplay API get_pp_num_states
  smu_get_current_power_state() - modifed arg0 to match Powerplay API get_current_power_state
  smu_sys_get_pp_feature_mask() - modifed signature to match Powerplay API get_ppfeature_status
  smu_sys_set_pp_feature_mask() - modifed arg0 to match Powerplay API set_ppfeature_status

Other Changes
  added 6 above smu Powerplay functions to swsmu_dpm_funcs
  removed special smu handling of above functions and called through Powerplay API
Signed-off-by: Darren Powell <darren.powell@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>