target/arm: Use FIELD definitions for CPACR, CPTR_ELx

We had a few CPTR_* bits defined, but missed quite a few.
Complete all of the fields up to ARMv9.2.
Use FIELD_EX64 instead of manual extract32.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220517054850.177016-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>