* Users can now use libbsd string.h and sys/cdefs.h functionality
(e.g., strlcpy, containerof) on Linux by just including
string.h or sys/cdefs.h. In other words, the includes are the same
on the Linux target as well as on chips targets (ESP32, etc.).
* libbsd linking is done by the linux component (belongs to common
components) now instead of handling it separately in each component
linux/lwip: Wrap some IO posix functions
* to workaourd the FreeRTOS EINTR issue (when building without lwip)
* to correctly choose the sub-system based on fd (when building with
lwip) -- passing control to either linux/system or to lwip
This commit also addapts tapio-if to provide DHCP client by default and
configurable settings for static IP
