app-emulation/qemu: Fix cross-compiling for MinGW (Windows)

app-emulation/qemu: Fix cross-compiling for MinGW (Windows)

Yes, this really works! By default, the configure script shoves
everything in the same standalone directory for Windows, hence the
need to specify more paths. It doesn't work from a standalone
directory unless you build it statically anyway because it can't find
the dependent DLLs in /usr/bin.

Package-Manager: Portage-2.3.76, Repoman-2.3.17
Signed-off-by: James Le Cuirot <chewi@gentoo.org>
Signed-off-by: Matthias Maier <tamiko@gentoo.org>