arm/tegra: rename board-dt.c to board-dt-tegra20.c

Tegra20 based boards will be handled by the current board-dt.c file. Tegra30
based boards will be handled by a new board-dt-tegra30.c file. Hence rename
the existing board-dt.c to board-dt-tegra20.c to reflect its use.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index 26ff456..813af0d 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -28,7 +28,7 @@
 obj-$(CONFIG_MACH_SEABOARD)             += board-seaboard.o
 obj-$(CONFIG_MACH_SEABOARD)             += board-seaboard-pinmux.o
 
-obj-$(CONFIG_MACH_TEGRA_DT)             += board-dt.o
+obj-$(CONFIG_MACH_TEGRA_DT)             += board-dt-tegra20.o
 obj-$(CONFIG_MACH_TEGRA_DT)             += board-harmony-pinmux.o
 obj-$(CONFIG_MACH_TEGRA_DT)             += board-seaboard-pinmux.o
 obj-$(CONFIG_MACH_TEGRA_DT)             += board-paz00-pinmux.o