move _WANT_FREEBSD macros from bsd-user/freebsd/os-syscall.c to
include/qemu/osdep.h in order to pull some struct defintions needed
later in the build.
Signed-off-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Karim Taha <kariem.taha2.7@gmail.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>