Merge remote-tracking branch 'remotes/afaerber/tags/qom-cpu-for-peter' into staging

Merge remote-tracking branch 'remotes/afaerber/tags/qom-cpu-for-peter' into staging

QOM CPUState and X86CPU

* Add CPUClass documentation
* Clean up X86CPU APIC realization
* Cleanups around cpu_init()

# gpg: Signature made Tue Mar 10 17:27:28 2015 GMT using RSA key ID 3E7E013F
# gpg: Good signature from "Andreas Färber <afaerber@suse.de>"
# gpg:                 aka "Andreas Färber <afaerber@suse.com>"

* remotes/afaerber/tags/qom-cpu-for-peter:
  cpu: Make cpu_init() return QOM CPUState object
  unicore32: Use uc32_cpu_init()
  m68k: Use cpu_m68k_init()
  target-unicore32: Make uc32_cpu_init() return UniCore32CPU
  target-i386: Clean up misuse of qdev_init() in realize method
  cpu: Add missing documentation for some CPUClass methods

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