Fix libc integration with WiseConnect

[jerome-pouiller]

WiseConnect import its own version of Posix headers and access to private attributes. Thus:

• support 917 may break in an horrible way if all the parts do not compile with the same headers
• the 917 support only compile with toolchain provided by Zephyr-SDK (ie. it does not work with ZEPHYR_TOOLCHAIN_VARIANT=gnuarmemb)
• things may break on toolchain update
• compatibility issues with picolib

Reported to Manav

[jerome-pouiller]

May be already fixed with WiseConnect 3.3