If FILESYSTEM_PERMS_TABLES was not defined, the default was selected by the
packages.bbclass. This made it difficult for a recipe or layer to 'append'
to the default.
Copy the default into the bitbake.conf, allowing future _append and += style
actions.
Default was remove from package.bbclass. If a value is not set, only the
built-in perms fixes will be used.
Signed-off-by: Mark Hatle <mark.hatle@windriver.com> Signed-off-by: Ross Burton <ross.burton@intel.com>