[U-Boot] [PATCH V2] Block: Remove MG DISK support

[Marek Vasut]

Any objections?

> This driver is unused and obsolete.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Wolfgang Denk <wd at denx.de>
> Cc: unsik Kim <donari75 at gmail.com>

Best regards,
Marek Vasut