drm/amd/pm: new v3 SmuMetrics data structure for Sienna Cichlid

structure changed in smc_fw_version >= 0x3A4900,
    "uint16_t VcnActivityPercentage" replaced with
    "uint16_t VcnUsagePercentage0" and "uint16_t VcnUsagePercentage1"

Signed-off-by: Danijel Slivka <danijel.slivka@amd.com>
Acked-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>