[coreboot] [Trivial] Patches for SB600 spi driver controller

Hi, all I had changed the Copyright of sb600spi.c. Best wishes Jason Wang BeiJing Technology Development Center Advanced Micro Devices (AMD) Signed-off-by:  Jason Wang<Qingpei.wang@amd.com> Reviewed-by: Joe, Bao <Zheng.Bao@amd.com>