kernel/mingw: add target libraries

Add several development libraries to the build of the mingw cross-compiler
to be used on target

Libraries:
PDCurses (port of the ncurses library)
GnuRX (the regex library)
DirectX
OpenGL

Signed-off-by: Bart vdr. Meulen <bartvdrmeulen@gmail.com>
[yann.morin.1998@anciens.enib.fr: don't show DX and RX versions if disabled]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 source "config/backend.in"

 source "config/global.in"

 source "config/target.in"

 source "config/toolchain.in"

 source "config/kernel.in"

 source "config/binutils.in"

 source "config/cc.in"

 source "config/libc.in"

 source "config/debug.in"

 source "config/companion_libs.in"

 source "config/companion_tools.in"

 source "config/test_suite.in"