target/arm64: kvm debug set target_el when passing exception to guest

target/arm64: kvm debug set target_el when passing exception to guest

When we are debugging the guest all exceptions come our way but might
be for the guest's own debug exceptions. We use the ->do_interrupt()
infrastructure to inject the exception into the guest. However, we are
missing a full setup of the exception structure, causing an assert
later down the line.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20181109152119.9242-4-alex.bennee@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>