Switch to `NET_SOCKET_REGISTER` mechanism over the offloaded API
registration.
Including the following fixes from the review:
* The fd returned by the socket accept call needs to be finalized,
similar to how it is done for socket creation.
* sl_RecvFrom() in TI SimpleLink Host driver does not support NULL
pointers for 'from' address and address length, and sl_SendTo() does
not ignore the destination address when in connection mode, so passing
NULL would cause a failure. These issues have been reported to TI
(CC3X20SDK-1970, CC3X20SDK-1971).
Let's use sl_Recv and sl_Send to implement recvfrom/sendto in the case
of NULL addresses.
* simplelink_poll() should not process negative file descriptors in the
fds array after sl_Selecti() returns. A negative fd value indicates
that the entry is invalid and should be ignored.
Signed-off-by: Vincent Wan <vincent.wan@linaro.org>
Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
