MAINTAINERS: Fix Florian Fainelli's email address

Commit 31345a0f ("MAINTAINERS: Replace my email address") added 13
instances of ...@broadcom.com and one of only ...@broadcom. I didn't
double check if Broadcom really owns that TLD, but git send-email
doesn't accept it, so add ".com" to that one bogous(?) instance.

Fixes: 31345a0f

 ("MAINTAINERS: Replace my email address")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>