drm/amd/amdgpu: Add smu_pptable module parameter

Temporarily add smu_pptable module parameter for aldebaran.This is used
to force soft PPTable use overriding any VBIOS PPTable.

Signed-off-by: Lijo Lazar <Lijo.Lazar@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Reviewed-by: Kevin Wang <kevin1.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>