linux-wrs: allow optional features via KERNEL_FEATURES variable

Fixes [BUGID #199]

Reinstate the ability to specify optional/additional kernel features
when updating the tree.

This is done via the variable KERNEL_FEATURES which specifies
a list of features to be appended to the current branch and
config. These features are part of the wrs_meta branch in the
kernel repository and hence are self contained within the
kernel tree waiting to be activated. This saves multiple
branches simply to allow a machine to have many profiles.

The kernel patching/configuration phases will locate these
features and add them to the meta_series, which in turn
modifies the tree.

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>

meta/recipes-kernel/linux/linux-wrs_git.bb

@@ -49,8 +49,11 @@ do_patch() {
 		exit 1
 	fi
 
-	# updates or generates the target description
-	updateme ${ARCH} ${WORKDIR}
+        # updates or generates the target description
+	if [ -n "${KERNEL_FEATURES}" ]; then
+	       addon_features="--features ${KERNEL_FEATURES}"
+	fi
+	updateme ${addon_features} ${ARCH} ${WORKDIR}
 	if [ $? -ne 0 ]; then
 		echo "ERROR. Could not update ${WRMACHINE}-${LINUX_KERNEL_TYPE}"
 		exit 1