Move the inclusion out of hw/hw.h, most files do not need it.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This controller is also present in i.MX5X devices but they are not
yet emulated by QEMU.
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NJean-Christophe Dubois <jcd@tribudubois.net>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>