target/arm: Implement HCR_EL2.TICAB,TOCU traps

target/arm: Implement HCR_EL2.TICAB,TOCU traps

For FEAT_EVT, the HCR_EL2.TICAB bit allows trapping of the ICIALLUIS
and IC IALLUIS cache maintenance instructions.

The HCR_EL2.TOCU bit traps all the other cache maintenance
instructions that operate to the point of unification:
 AArch64 IC IVAU, IC IALLU, DC CVAU
 AArch32 ICIMVAU, ICIALLU, DCCMVAU

The two trap bits between them cover all of the cache maintenance
instructions which must also check the HCR_TPU flag.  Turn the old
aa64_cacheop_pou_access() function into a helper function which takes
the set of HCR_EL2 flags to check as an argument, and call it from
new access_ticab() and access_tocu() functions as appropriate for
each cache op.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>