drm/amd/powerplay: fix memory leak in rv_hwmgr backend

vddc_dep_on_dal_pwrl and vq_budgeting_table are allocated and initialized
in rv_hwmgr_backend_init. Thus free the memory in rv_hwmgr_backend_fini

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>