Like most of the v7M memory mapped system registers, the systick
registers are accessible to privileged code only and user accesses
must generate a BusFault. We implement that for registers in
the NVIC proper already, but missed it for systick since we
implement it as a separate device. Correct the omission.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190617175317.27557-6-peter.maydell@linaro.org