shadow: replace static linking with dynamic libraries in a custom location and bundle...

shadow: replace static linking with dynamic libraries in a custom location and bundled with shadow

Despite our efforts to make static linking work, there have
been new reports of bizarre build failures:
https://lists.openembedded.org/g/openembedded-core/message/194006
https://lists.openembedded.org/g/openembedded-core/message/193907

This commit changes back to dynamic linking, but places
the libraries in a custom location, per RP's suggestion.

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>