There is new interest in the SD/MMC device emulation, so it
would be good to have more than only one maintainer / reviewer
for it.

Bin Meng proved by his contributions a deep understanding of the
SD cards internals, so let's add him to the corresponding section
in the MAINTAINERS file.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Bin Meng <bin.meng@windriver.com>
Message-Id: <20210216132841.1121653-1-f4bug@amsat.org>