configure: Infer licheck bitness from platform argument

We build our 32 bit Linux packages nowadays on Red Hat 64 bit with
-platform linux-g++-32. Honor this when selecting the right licheck
binary to use.

Change-Id: I08527295bc461c8cdd07e81a10c93a8f010b787d
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

configure

@@ -2965,11 +2965,21 @@ if [ -f "$relpath"/LICENSE.PREVIEW.COMMERCIAL ] && [ $COMMERCIAL_USER = "yes" ];
     EditionString="Technology Preview"
 elif [ $COMMERCIAL_USER = "yes" ]; then
     if [ $UNAME_SYSTEM = "Linux" ]; then
+        case "$PLATFORM" in
+        *-32)
+            Licheck=licheck32
+            ;;
+        *-64)
+            Licheck=licheck64
+            ;;
+        *)
             if file -L /bin/sh | grep -q "64-bit" ; then
                 Licheck=licheck64
             else
                 Licheck=licheck32
             fi
+            ;;
+        esac
     elif [ $UNAME_SYSTEM = "Darwin" ]; then
         Licheck=licheck_mac
     else