armv7: convert makefiles to Kbuild style

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/arch/arm/cpu/armv7/tegra30/Makefile b/arch/arm/cpu/armv7/tegra30/Makefile
index 04adb52..518d6d1 100644
--- a/arch/arm/cpu/armv7/tegra30/Makefile
+++ b/arch/arm/cpu/armv7/tegra30/Makefile
@@ -17,24 +17,4 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-include $(TOPDIR)/config.mk
-
-LIB	= $(obj)lib$(SOC).o
-
-COBJS	:= $(COBJS-y)
-SRCS	:= $(COBJS:.o=.c)
-OBJS	:= $(addprefix $(obj),$(COBJS))
-
-all:	$(obj).depend $(LIB)
-
-$(LIB):	$(OBJS)
-	$(call cmd_link_o_target, $(OBJS))
-
-#########################################################################
-
-# defines $(obj).depend target
-include $(SRCTREE)/rules.mk
-
-sinclude $(obj).depend
-
-#########################################################################
+obj- :=