target/arm: Add _aa64_ and _any_ versions of pmu_8_1 isar checks

target/arm: Add _aa64_ and _any_ versions of pmu_8_1 isar checks

Add the 64-bit version of the "is this a v8.1 PMUv3?"
ID register check function, and the _any_ version that
checks for either AArch32 or AArch64 support. We'll use
this in a later commit.

We don't (yet) do any isar_feature checks on ID_AA64DFR1_EL1,
but we move id_aa64dfr1 into the ARMISARegisters struct with
id_aa64dfr0, for consistency.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200214175116.9164-10-peter.maydell@linaro.org