iw: use PKG_CONFIG variable consistently
iw: use PKG_CONFIG variable consistently

Use the correct pkg-config version consistently.
Note: For quick&dirty cross compilation I used the following in .config:

PKG_CONFIG = false
NLLIBNAME = libnl-1
LIBS += -L../libnl-1.1/lib -lnl
CFLAGS += -I../libnl-1.1/include
CC := arm-linux-gcc

Signed-off-by: Johannes Stezenbach <93f8bb0eb2c659b85694486c41717eaf0fe23cd4@sig21.net>

Distrotech/iw,idor/iw,greearb/iw-ct,greearb/iw-ct,bcopeland/android_iw,ewa/iw-modified,SoluMachines/external_iw,ewa/iw-modified,TeamEOS/external_iw,chunyeow/iw,Distrotech/iw,SoluMachines/external_iw,cozybit/iw,timduru/platform-external-iw,bcopeland/android_iw,bw-oss/iw,OSLL/iw,OSLL/iw,idor/iw,cozybit/iw,CTU-IIG/802.11p-iw,bw-oss/iw,TeamEOS/external_iw,CTU-IIG/802.11p-iw,timduru/platform-external-iw,chunyeow/iw