[PATCH v2] MAINTAINERS: update Shawn's email to use kernel.org one

Shawn Guo [off-list ref] writes:

From: Shawn Guo <redacted>

Update my mailbox to use kernel.org one for handling kernel community
maintenance traffic.

Signed-off-by: Shawn Guo <redacted>
---
Changes since v1:
 - Update the commit log a bit

Hi Arnd,

I'm ready to switch the maintainer mailbox to kernel.org now.  Please
help apply the patch.  Thanks.

Applied to next/soc,

Thanks,

Kevin