lynx uses host C-compiler to build internal utility that is used to
generate files required for target build. On MacOS it uses internal
clang with MacOS system headers so host build fails due to MacOS is
not Linux

Forced to use OpenWrt host C compiler using --with-build-*
./configure flags

Signed-off-by: Sergey V. Lobanov <sergey@lobanov.in>

Signed-off-by: Jan Pavlinec <jan.pavlinec@nic.cz>

Signed-off-by: Leonid Esman <leonid.esman@gmail.com>

Based on https://github.com/kyak/openwrt-packages/tree/master/lynx
Tested on TP-Link TL-MR3020 v3

Signed-off-by: Leonid Esman <leonid.esman@gmail.com>