drm/amd/display: Acquire FCLK DPM levels on DCN32

[Why & How]
Acquire FCLK DPM levels to properly construct DML clock limits. Further
add new logic to keep number of indices for each clock in clk_mgr.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Dillon Varone <Dillon.Varone@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>