linux: add option to specify config fragments

Signed-off-by: Floris Bos <bos@je-eigen-domein.nl>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Tested-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Tested-by: Gergely Imreh <imrehg@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

linux/Config.in

@@ -164,6 +164,12 @@ config BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE
 	  Note: this can be a defconfig file or a complete .config file,
 	  which can later be saved back with make linux-update-(def)config.
 
+config BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES
+	string "Additional configuration fragment files"
+	help
+	  A space-separated list of kernel configuration fragment files,
+	  that will be merged to the main kernel configuration file.
+
 #
 # Binary format
 #

linux/linux.mk

@@ -182,6 +182,7 @@ KERNEL_SOURCE_CONFIG = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE))
 endif
 
 LINUX_KCONFIG_FILE = $(KERNEL_SOURCE_CONFIG)
+LINUX_KCONFIG_FRAGMENT_FILES = $(call qstrip,$(BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES))
 LINUX_KCONFIG_EDITORS = menuconfig xconfig gconfig nconfig
 LINUX_KCONFIG_OPTS = $(LINUX_MAKE_FLAGS)