drm/amd/display: Correct bw_params population

[Why]
Underflow observed during P010 video playback on
dcn314 due to incorrectly populated bw_params

[How]
Populate fclk, memclk and voltage in bw_params with
values from max pstate rather than min pstate

Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Daniel Miess <Daniel.Miess@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>