Refactor netlib_check_ipconnectivity() to use gateway/router ping instead
of DNS server ping for network connectivity checks. Add IPv6 support.
Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>
Replace app-side includes of <debug.h> with <nuttx/debug.h> to use the
header from the NuttX tree explicitly after the header move.
Signed-off-by: Piyush Patle <piyushpatle228@gmail.com>