x86: Correct typo of Miao Yan's email address

Miao Yan's email address is wrong in fw_cfg.c. Fix it.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/qemu/fw_cfg.c

 /*
- * (C) Copyright 2015 Miao Yan <yanmiaoebst@gmail.com>
+ * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */