net: sockets: remove POSIX_NAMES dependency on SOCKETS_OFFLOAD
net: sockets: remove POSIX_NAMES dependency on SOCKETS_OFFLOAD

This is no longer required since drivers implementing the sockets
offload interface were migrated to use pure zsock_ instead of
raw POSIX types and functions.

Signed-off-by: Adam Porter <4f8b3b95d5f60c80ed7be8d1ae91cde6b204ba68@gmail.com>

nashif/zephyr,Vudentz/zephyr,galak/zephyr,galak/zephyr,nashif/zephyr,galak/zephyr,finikorg/zephyr,Vudentz/zephyr,nashif/zephyr,nashif/zephyr,nashif/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,Vudentz/zephyr