don't fail if there are no dtbs

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>

SVN-Revision: 39141

target/linux/omap/image/Makefile

@@ -10,9 +10,9 @@ include $(INCLUDE_DIR)/image.mk
 define Image/BuildKernel
 	cp $(KDIR)/zImage $(BIN_DIR)/openwrt-$(BOARD)-zImage
 	-mkdir $(BIN_DIR)/dtbs
-	$(CP) $(LINUX_DIR)/arch/arm/boot/dts/am335x*.dtb $(BIN_DIR)/dtbs/
-	$(CP) $(LINUX_DIR)/arch/arm/boot/dts/omap3*.dtb $(BIN_DIR)/dtbs/
-	$(CP) $(LINUX_DIR)/arch/arm/boot/dts/omap4*.dtb $(BIN_DIR)/dtbs/
+	-$(CP) $(LINUX_DIR)/arch/arm/boot/dts/am335x*.dtb $(BIN_DIR)/dtbs/
+	-$(CP) $(LINUX_DIR)/arch/arm/boot/dts/omap3*.dtb $(BIN_DIR)/dtbs/
+	-$(CP) $(LINUX_DIR)/arch/arm/boot/dts/omap4*.dtb $(BIN_DIR)/dtbs/
 endef
 
 define Image/Build