libc/mingw: replace mingw32 with generic mingw

Replace the 32-bit-only mingw32 with mingw-w64 that is capable
of building toolchains for both 32-bit and 64-bit Windows.

kernel/mingw: replace mingw32 with generic Windows
kernel/windows: New windows kernel supporting 32 and 64 bit arch
libc/mingw: Remove old options
patches: Remove old mingw libc options' patches

Signed-off-by: "Yann Diorcet" <diorcet.yann@gmail.com>
[yann.morin.1998@free.fr: array var in libc/mingw.sh, typos]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <b045ac08fc9eac2e5ee3.1352898499@blackmint>
Patchwork-Id: 198901

 reporter_name="Yann Diorcet <diorcet.yann@gmail.com>"

 reporter_url=""

 reporter_comment="Config to build cross-compiler with mingw as kernel type for

 64 bits Windows target"