target/arm: Flush tlb for ASID changes in EL2&0 translation regime

target/arm: Flush tlb for ASID changes in EL2&0 translation regime

Since we only support a single ASID, flush the tlb when it changes.

Note that TCR_EL2, like TCR_EL1, has the A1 bit that chooses between
the two TTBR* registers for the location of the ASID.

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: 20200206105448.4726-31-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>