target-arm: Change cpu_arm_init() return type to ARMCPU
Make cpu_arm_init() return a QOM ARMCPU, so that we don't need to
obtain an ARMCPU through arm_env_get_cpu() in machine init code.
This requires to adjust the inclusion site of cpu-qom.h and in turn,
forward-looking, to homogenize its include order.
cpu_init() must still return a CPUARMState for backwards and
cross-target compatibility, so adjust the cpu_init macro.
Signed-off-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>