coreutils: add PACKAGECONFIG for single-binary

coreutils: add PACKAGECONFIG for single-binary

Add PACKAGECONFIG for single-binray. Disable it by default.

When enabled, there would only be one binary file /usr/bin/coreutils, other
files like 'ls' are text files containing contents like:

  #!/usr/bin/coreutils --coreutils-prog-shebang=ls

And the size of the rpm package reduces from 849K to 519K.

Default to disable this option to keep the traditional behaviour.

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>