drm/amd/pm: Fix a potential gpu_metrics_table memory leak

Memory is allocated for gpu_metrics_table in
smu_v13_0_4_init_smc_tables(), but not freed in
smu_v13_0_4_fini_smc_tables(). This may cause memory leaks, fix it.

Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Zhen Ni <nizhen@uniontech.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>