venice2: move device tree to fix build error

Commit 5ab502cb gathered all device tree sources
to arch/$(ARCH)/dts/.
So tegra124-venice2.dts also must go to arch/arm/dts directory
to build venice2 board.

(Commit 5ab502cb had been posted before venice2 board support
was merged. So an unvisible conflict happened.)

Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@ti.com>

arch/arm/dts/Makefile

@@ -2,7 +2,6 @@ dtb-$(CONFIG_EXYNOS5) += exynos5250-arndale.dtb \
 	exynos5250-snow.dtb \
 	exynos5250-smdk5250.dtb \
 	exynos5420-smdk5420.dtb
-
 dtb-$(CONFIG_TEGRA) += tegra20-harmony.dtb \
 	tegra20-medcom-wide.dtb \
 	tegra20-paz00.dtb \
@@ -16,8 +15,8 @@ dtb-$(CONFIG_TEGRA) += tegra20-harmony.dtb \
 	tegra30-beaver.dtb \
 	tegra30-cardhu.dtb \
 	tegra30-tec-ng.dtb \
-	tegra114-dalmore.dtb
+	tegra114-dalmore.dtb \
-
+	tegra124-venice2.dtb
 dtb-$(CONFIG_ZYNQ) += zynq-zc702.dtb \
 	zynq-zc706.dtb \
 	zynq-zed.dtb \