libtirpc: using sys/queue.h from staging

Now that musl toolchains depend on netbsd-queue package, a
implementation of sys/queue.h will always be available in the
staging directory, so we can remove the patch that adds a local
sys/queue.h implementation.

Signed-off-by: Sergio Prado <sergio.prado@e-labworks.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>