ARM: dts: kirkwood: add kirkwood-ds112.dtb to Makefile

Commit 2d0a7add ("ARM: Kirkwood: Add support for many Synology
NAS devices") created the new file kirkwood-ds112.dts but did not
add it to the Makefile.

Fixes: 2d0a7add ("ARM: Kirkwood: Add support for many Synology NAS devices")
Signed-off-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>

arch/arm/boot/dts/Makefile

@@ -177,6 +177,7 @@ dtb-$(CONFIG_MACH_KIRKWOOD) += \
 	kirkwood-ds109.dtb \
 	kirkwood-ds110jv10.dtb \
 	kirkwood-ds111.dtb \
+	kirkwood-ds112.dtb \
 	kirkwood-ds209.dtb \
 	kirkwood-ds210.dtb \
 	kirkwood-ds212.dtb \