Samsung mach/soc changes for v5.11

1. Do not use of_machine_is_compatible() in early CPU hotplug core. Full
   device tree walk causes "suspicious RCU usage" warnings.
2. Clear prefetch bits in default l2c_aux_val of L310 L2C - they are not
   needed.
3. Extend cpuidle support to P4 Note boards (Exynos4412).