iw: remove android-nl.c with unneeded workaround

iw: remove android-nl.c with unneeded workaround

The workaround might have been necessary in the past, however now it
produces the following error:

  .../libnl.a(attr.o): multiple definition of 'nla_put_flag'
  .../android-nl.o: previous definition here
  collect2: error: ld returned 1 exit status

TEST=Built AOSP tree with this patchset, tested the generated iw binary.

Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>