MAINTAINERS: exclude other Socionext SoC DT files from ARM/UNIPHIER entry

There are several product lines in Socionext.  I maintain only
DT files prefixed with "uniphier".
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>

MAINTAINERS

@@ -2046,7 +2046,7 @@ F:	arch/arm/boot/dts/uniphier*
 F:	arch/arm/include/asm/hardware/cache-uniphier.h
 F:	arch/arm/mach-uniphier/
 F:	arch/arm/mm/cache-uniphier.c
-F:	arch/arm64/boot/dts/socionext/
+F:	arch/arm64/boot/dts/socionext/uniphier*
 F:	drivers/bus/uniphier-system-bus.c
 F:	drivers/clk/uniphier/
 F:	drivers/gpio/gpio-uniphier.c