lib/oe/recipeutils.py: add support for BBFILES_DYNAMIC

lib/oe/recipeutils.py: add support for BBFILES_DYNAMIC

Instead of relying on value of BBFILES from bitbake, devtool
parses the layer.conf because the layer might not be in bblayers.conf.
And it currently does not consider the value of BBFILES_DYNAMIC because
of which recipes, in paths defined by BBFILES_DYNAMIC, upgraded
using devtool end up in wrong location.

Include the code from bitbake to append values to BBFILES based on
what is in BBFILES_DYNAMIC too.

Signed-off-by: Naveen Saini <naveen.kumar.saini@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>