MAINTAINERS: update brcmstb entries

Add Gregory Fong and myself as maintainers for the brcmstb platform
along with Brian Norris and Marc Carino.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

MAINTAINERS

@@ -2087,6 +2087,8 @@ F:	arch/arm/include/debug/bcm63xx.S
 BROADCOM BCM7XXX ARM ARCHITECTURE
 M:	Marc Carino <marc.ceeeee@gmail.com>
 M:	Brian Norris <computersforpeace@gmail.com>
+M:	Gregory Fong <gregory.0xf0@gmail.com>
+M:	Florian Fainelli <f.fainelli@gmail.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	arch/arm/mach-bcm/*brcmstb*