package/nodejs: symlink /usr/lib/node_modules/.bin/* to /usr/bin

This patch symlinks all executables in /usr/lib/node_modules/.bin
to /usr/bin so that node.js modules installed using
BR2_PACKAGE_NODEJS_MODULES_ADDITIONAL are accessible from the command line.

Signed-off-by: Martin Bark <martin@barkynet.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>