MAINTAINERS: update entry for Linus Walleij

I prefer to use the Linaro mail address for the MAINTAINERS
entry due to heavy mail traffic. Take this opportunity to
update the wildcards, including removing the stmpe* drivers
from the ux500 entry since these are not specific to that
machine.

Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>