linux-yocto*: append to KERNEL_FEATURES instead of assigning
It is sometimes useful for KERNEL_FEATURES to be set in a machine
or other configuration file. The linux-yocto recipes currently
initialize the variable, which clobbers any values set by .conf
files.
Appending to the variables allows these settings to propagate to
the kernel configuration, while maintaining the existing set of
added kernel features.
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com> Signed-off-by: Saul Wold <sgw@linux.intel.com>
