MAINTAINERS: Add exynos filename match to ARM/S5P EXYNOS ARM ARCHITECTURES

This will help direct patches related to exynos to the
linux-samsung-soc mailing list for discussion.

Suggested by Joe Perches.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

MAINTAINERS

@@ -1135,6 +1135,7 @@ L:	linux-samsung-soc@vger.kernel.org (moderated for non-subscribers)
 S:	Maintained
 F:	arch/arm/mach-s5p*/
 F:	arch/arm/mach-exynos*/
+N:	exynos
 
 ARM/SAMSUNG MOBILE MACHINE SUPPORT
 M:	Kyungmin Park <kyungmin.park@samsung.com>