drm/amd/pm: correct gpu metrics related data structures V3

To make sure they are naturally aligned. Also updating the
data type for link_speed/width for future PCIE5 support.

V2: define new structures with minor version bumped
V3: update data type of energy_accumulator as 64bit and
    drop unnecessary padding members

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>