drm/amd/pm: Vangogh: Add new gpu_metrics_v2_4 to acquire gpu_metrics

To acquire the voltage and current info from gpu_metrics interface,
but gpu_metrics_v2_3 doesn't contain them, and to be backward compatible,
add new gpu_metrics_v2_4 structure.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Wenyou Yang <WenYou.Yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>