hvf: arm: Use macros for sysreg shift/masking

hvf: arm: Use macros for sysreg shift/masking

We are parsing the syndrome field for sysregs in multiple places across
the hvf code, but repeat shift/mask operations with hard coded constants
every time. This is an error prone approach and makes it harder to reason
about the correctness of these operations.

Let's introduce macros that allow us to unify the constants used as well
as create new helpers to extract fields from the sysreg value.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alexander Graf <agraf@csgraf.de>
Reviewed-by: Cameron Esfahani <dirty@apple.com <mailto:dirty@apple.com>>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20220209124135.69183-1-agraf@csgraf.de
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>