drm/amdgpu: add ELM/BAF support to dce_v11_0_pick_pll (v2)

New PLL scheme on ELM/BAF.

v2: squash in pll fix.  Plls are part of the phys.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>