npm.bbclass: avoid building target nodejs for native npm recipes
The current recipe unconditionally RDEPENDS on nodejs (the target one).
When building on the "-native recipe" of "BBCLASSEXTEND native" recipe,
the target nodejs is unnecessarily built.
This patch fixes this by only RDEPENDS on nodejs when building for the target.
Signed-off-by: Yoann Congal <yoann.congal@smile.fr> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
