libc/net: Add inet_pton()
libc/net: Add inet_pton()

inet_pton(): converts an address in its standard text presentation form into its numeric binary form.

This is back-ported from Nuttx commit cf99fb4.

pillip8282/TizenRT,an4967/TizenRT,jeongchanKim/TizenRT,junmin-kim/TizenRT,sunghan-chang/TizenRT,junmin-kim/TizenRT,an4967/TizenRT,sunghan-chang/TizenRT,pillip8282/TizenRT,jsdosa/TizenRT,jsdosa/TizenRT,JeonginKim/TizenRT,an4967/TizenRT,an4967/TizenRT,chanijjani/TizenRT,Samsung/TizenRT,jeongarmy/TizenRT,jsdosa/TizenRT,an4967/TizenRT,HONGCHAEHEE/TizenRT,jeongchanKim/TizenRT,pillip8282/TizenRT,sunghan-chang/TizenRT,jeongarmy/TizenRT,chanijjani/TizenRT,jeongchanKim/TizenRT,davidfather/TizenRT,junmin-kim/TizenRT,sunghan-chang/TizenRT,junmin-kim/TizenRT,HONGCHAEHEE/TizenRT,Samsung/TizenRT,HONGCHAEHEE/TizenRT,junmin-kim/TizenRT,sunghan-chang/TizenRT,davidfather/TizenRT,davidfather/TizenRT,JeonginKim/TizenRT,Samsung/TizenRT,chanijjani/TizenRT,Samsung/TizenRT,jsdosa/TizenRT,Samsung/TizenRT,jsdosa/TizenRT,jeongchanKim/TizenRT,sunghan-chang/TizenRT,jeongarmy/TizenRT,pillip8282/TizenRT,HONGCHAEHEE/TizenRT,jeongarmy/TizenRT,HONGCHAEHEE/TizenRT,jeongchanKim/TizenRT,jeongarmy/TizenRT,JeonginKim/TizenRT,jsdosa/TizenRT,jeongchanKim/TizenRT,pillip8282/TizenRT,junmin-kim/TizenRT,chanijjani/TizenRT,junmin-kim/TizenRT,jeongchanKim/TizenRT,Samsung/TizenRT,JeonginKim/TizenRT,jsdosa/TizenRT,pillip8282/TizenRT,jeongarmy/TizenRT,davidfather/TizenRT,sunghan-chang/TizenRT,pillip8282/TizenRT,chanijjani/TizenRT,an4967/TizenRT,davidfather/TizenRT,davidfather/TizenRT,JeonginKim/TizenRT,JeonginKim/TizenRT,davidfather/TizenRT,jeongarmy/TizenRT,chanijjani/TizenRT,Samsung/TizenRT,an4967/TizenRT,HONGCHAEHEE/TizenRT,chanijjani/TizenRT