drm/amd/pm: parse pp_handle under appropriate conditions

amdgpu_dpm_is_overdrive_supported is a common API across all
asics, so we should cast pp_handle into correct structure
under different power frameworks.

v2: using return directly to simplify code
v3: SI asic does not carry od_enabled member in pp_handle, and update Fixes tag

Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2541


Fixes: eb4900aa ("drm/amdgpu: Fix kernel NULL pointer dereference in dpm functions")
Suggested-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Guchun Chen <guchun.chen@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org