QOM CPUState and X86CPU

* Cleanups for -cpu ...,enforce

* remotes/afaerber/tags/qom-cpu-for-peter:
  target-i386: Disable SVM by default in KVM mode
  target-i386: Don't enable nested VMX by default
  target-i386: Remove unsupported bits from all CPU models
  target-i386: Disable CPUID_ACPI by default in KVM mode
  target-i386: Rename KVM auto-feature-enable compat function
  pc: Create pc_compat_2_1() functions

Conflicts:
	hw/i386/pc_piix.c
	hw/i386/pc_q35.c
[PMM: Fixed minor textual conflicts]

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>