setup-defconfig: move from meta-arago to meta-ti

* Moved the setup-defconfig.inc file from meta-arago to meta-ti.
  This functionality is used by the SDKs to allow the option for
  using an in-tree configuration file for the kernel build.
* This option was chosen to make it easy for other layers to
  override the config with their own using the normal OE method
  of specifying a defconfig file in their layer rather than having
  to use some custom variable setting.

Signed-off-by: Chase Maupin <Chase.Maupin@ti.com>
Signed-off-by: Denys Dmytriyenko <denys@ti.com>

recipes-kernel/linux/setup-defconfig.inc

@@ -0,0 +1,26 @@
+# Check the defconfig file and see if it points to an in kernel
+# defconfig that should be used, or if it is a complete config file
+
+addtask setup_defconfig before do_configure after do_patch
+do_setup_defconfig() {
+    # Always copy the defconfig file to .config to keep consistency
+    # between the case where there is a real config and the in kernel
+    # tree config
+    cp ${WORKDIR}/defconfig ${S}/.config
+}
+
+# define our own do_configure that will:
+#   1. Check the .config file and see if string use-kernel-config= is present
+#   2. If the use-kernel-config string is present parse out the config to use
+#      and run make ${config}
+#   3. else run yes '' | oe_runmake oldconfig like the default do_configure
+#      does
+do_configure() {
+    config=`cat ${S}/.config | grep use-kernel-config | cut -d= -f2`
+    if [ "x${config}" != "x" ]
+    then
+        oe_runmake ${config}
+    else
+        yes '' | oe_runmake oldconfig
+    fi
+}