target/arm: Implement GPC exceptions

target/arm: Implement GPC exceptions

Handle GPC Fault types in arm_deliver_fault, reporting as
either a GPC exception at EL3, or falling through to insn
or data aborts at various exception levels.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230620124418.805717-19-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>