drm/amd: Fix SMU 13.0.4/13.0.11 GPU metrics average power

The average power for the GPU metrics sysfs file contains the input
power not the average power.  The member that is set is called average
power though, so correct it to the right value.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>