target/arm: Add VHE timer register redirection and aliasing

target/arm: Add VHE timer register redirection and aliasing

Apart from the wholesale redirection that HCR_EL2.E2H performs
for EL2, there's a separate redirection specific to the timers
that happens for EL0 when running in the EL2&0 regime.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200206105448.4726-30-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>