Implement the code which updates the FPCCR register on an
exception entry where we are going to use lazy FP stacking.
We have to defer to the NVIC to determine whether the
various exceptions are currently ready or not.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20190416125744.27770-12-peter.maydell@linaro.org