Windows: Fix version embedding in CMake binaries

In commit 5b9da05b7a (Windows: Embed version information into CMake
binaries, 2017-10-25) we left out `<winres.h>` since MinGW does not have
the header, but it is needed for the `VS_VERSION_INFO` macro.  Provide
the macro ourselves.

Suggested-by: Christian Pfeiffer <[email protected]>

Source/CMakeVersion.rc.in

@@ -7,6 +7,9 @@
 #define VER_PRODUCTVERSION          @CMake_VERSION_MAJOR@,@CMake_VERSION_MINOR@,@CMake_VERSION_PATCH@
 #define VER_PRODUCTVERSION_STR      "@CMake_VERSION@\0"
 
+/* Version-information resource identifier.  */
+#define VS_VERSION_INFO 1
+
 VS_VERSION_INFO VERSIONINFO
 FILEVERSION    	VER_FILEVERSION
 PRODUCTVERSION 	VER_PRODUCTVERSION