Add support for EXTRA_OENPM arguments to set node-gyp variables for
example. This allows use of shared librariess, avoid download
of external sources or build from source.
Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>