devtool/standard: set a preferred provider when adding a new recipe with devtool
A recipe added with "devtool add" requires to be able to take precedence on recipes
previously defined with PREFERRED_PROVIDER.
By adding the parameter "--provides" to "devtool add" it is possible to specify
an element to be provided by the recipe. A devtool recipe can override a previous
PREFERRED_PROVIDER using the layer configuration file in the workspace.
E.g.
devtool add my-libgl git@git://my-libgl-repository --provides virtual/libgl
[YOCTO #10415]
Signed-off-by: Juan M Cruz Alcaraz <juan.m.cruz.alcaraz@linux.intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
