soletta: Add Node.js bindings to soletta package

[nagineni]

This patch exports the needed variables to build Node.js bindings and add them to the soletta package.

[1] This [2] ostroproject/meta-ostro#115 (Enable bindings by default) [3] ostroproject/meta-iot-web#10 (Add soletta-nodejs package to Node.js runtime package group)

This replaces #71

Signed-off-by: Sudarsana Nagineni sudarsana.nagineni@intel.com

[nagineni]

@brunobottazzini @mythi PTAL

Test build is green with all the changes[1], [2] and [3]: https://github.com/ostroproject/ostro-os/pull/66

[mythi]

+1

[brunobottazzini]

+1