wpa_supplicant: add needed source file
wpa_supplicant: add missing macros
libnl: add dummies needed by wpa backend driver
merge user lx_emul from wpa_supplicant to libnl
dde_linux: rename linux/if.h in libnl

Definitions from this header are also needed by wpa_supplicant. It is
therefore included in the user lx_emul env. This results in compiling
errors, however.