Add GFX RAS error count reset function.

v2: remove xcp operation.
    only select_se_sh when instance number is more than 1.
v3: add check for se_num before select_se_sh.
    change instance from 0 to xcc_id for register access.

Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>