MicroPython overrides the axTLS port configuration file, but fails to
include <arpa/inet.h> (needed for htonl) and <sys/time.h> (needed for
gettimeofday). This results in build failures with compilers which do not
support implicit function declarations (which were removed from C in 1999).
This commit adds back the needed headers that were removed in this commit:
bd08017309
Signed-off-by: Damien George <damien@micropython.org>