Allow overriding Android NDK host on Windows

The -android-ndk-host argument to configure existed in the shell
script, but not in the Windows version. When using a 64-bit NDK
but a 32-bit host compiler (which is what we bundle with our
SDK), we would not detect the correct NDK host, making it impossible
to build Qt with this combo.

[ChangeLog][Android] Added -android-ndk-host configure option on
Windows.

Change-Id: Ie6a92b66e6875ed53f46fe41ecced70c3ec67585
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>