fix generated Makefile for Windows builds made on *nix (1.1.1d)

fix generated Makefile for Windows builds made on *nix (1.1.1d)

The fix consists of putting all destination directories
between double-quotes to make the default (and any custom)
prefixes containing spaces to work when doing 'make install'.

Also enable CI test with x86 mingw cross-build.

[extended tests]

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/11434)