linux: support multiple custom DTS files

[Thomas: fix minor typo in help text.]

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

linux/Config.in

@@ -323,10 +323,12 @@ config BR2_LINUX_KERNEL_INTREE_DTS_NAME
 	  dts files to build, separated by spaces.
 
 config BR2_LINUX_KERNEL_CUSTOM_DTS_PATH
-	string "Device Tree Source file path"
+	string "Device Tree Source file paths"
 	depends on BR2_LINUX_KERNEL_USE_CUSTOM_DTS
 	help
-	  Path to the device tree source file
+	  Path to the device tree source files. You can
+	  provide a list of dts paths to copy and build,
+	  separated by spaces.
 
 endif
 

linux/linux.mk

@@ -264,7 +264,7 @@ endif
 # configuration has changed.
 define LINUX_BUILD_CMDS
 	$(if $(BR2_LINUX_KERNEL_USE_CUSTOM_DTS),
-		cp $(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH) $(KERNEL_ARCH_PATH)/boot/dts/)
+		cp $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH)) $(KERNEL_ARCH_PATH)/boot/dts/)
 	$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_TARGET_NAME)
 	@if grep -q "CONFIG_MODULES=y" $(@D)/.config; then 	\
 		$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) modules ;	\