package/linux: fix custom dts files handling

Custom dts files are still conditionally copied based on non existing
boolean. So it is currently not possible to use custom dts file(s) at all.

List of dts files is now iterated and files are copied into dedicated kernel arch dir.

Signed-off-by: Rafal Susz <rafal.susz@gmail.com>
Tested-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

linux/linux.mk

@@ -370,8 +370,9 @@ endif
 # Compilation. We make sure the kernel gets rebuilt when the
 # configuration has changed.
 define LINUX_BUILD_CMDS
-	$(if $(BR2_LINUX_KERNEL_USE_CUSTOM_DTS),
-		cp -f $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH)) $(KERNEL_ARCH_PATH)/boot/dts/)
+	@for dts in $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH)); do \
+		cp -f $${dts} $(KERNEL_ARCH_PATH)/boot/dts/ ;   \
+	done
 	$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_TARGET_NAME)
 	@if grep -q "CONFIG_MODULES=y" $(@D)/.config; then	\
 		$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) modules ;	\
@@ -482,9 +483,9 @@ $(error No kernel configuration file specified, check your BR2_LINUX_KERNEL_CUST
 endif
 endif
 
-ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT)$(KERNEL_DTS_NAME),y)
+ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT):$(strip $(KERNEL_DTS_NAME)),y:)
 $(error No kernel device tree source specified, check your \
-BR2_LINUX_KERNEL_USE_INTREE_DTS / BR2_LINUX_KERNEL_USE_CUSTOM_DTS settings)
+BR2_LINUX_KERNEL_INTREE_DTS_NAME / BR2_LINUX_KERNEL_CUSTOM_DTS_PATH settings)
 endif
 
 endif # BR_BUILDING