target/arm: Implement HCR_EL2.AT handling

The FEAT_NV HCR_EL2.AT bit enables trapping of some address
translation instructions from EL1 to EL2.  Implement this behaviour.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Miguel Luis <miguel.luis@oracle.com>
1 file changed