conf/layer.conf: add BBFILES_DYNAMIC and dynamic layers

some recipes under meta-oe have dependency on meta-python,
and test_world of yocto-check-layer will failed with error
like:

ERROR: test_world (common.CommonCheckLayer)
ERROR: Nothing PROVIDES 'python3-pytoml-native' (but
/meta-openembedded/meta-oe/recipes-extended/mozjs/mozjs_60.9.0.bb
DEPENDS on or otherwise requires it). Close matches:
  python3-numpy-native
  python3-pycairo-native
  python3-rpm-native
ERROR: Required build target 'meta-world-pkgdata' has no buildable
providers.
Missing or unbuildable dependency chain was: ['meta-world-pkgdata',
'mozjs', 'python3-pytoml-native']

fix by make these recipes only active when identified layers are
present

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/dynamic-layers/meta-python/recipes-connectivity/lirc/lirc/lirc.tmpfiles

@@ -0,0 +1 @@
+d /run/lirc 0755 root root -