fix WINVER #ifdef for QS_TOUCH and QS_POINTER

The condition in WinUser.h is _WIN32_WINNT >= 0x0602.
This change is a backport of
qtbase/e26ed09102e2eb350eb072decbd670b7d515be45

Change-Id: I0725e65948528889623a0b0ff290745996a8b0a3
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>