drm/amd/pm: Add vclk and dclk sysnode for GC 9.4.3

Expose sysfs vclck and dclk entries for GC version 9.4.3

Signed-off-by: Asad Kamal <asad.kamal@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>