x86: Move local APIC initialization out of initCPU.

The APIC can (and probably should) set its version register on its
own. Also it already configures its CPUID register when associated
with a CPU and doesn't need initCPU to do that.

Change-Id: I4611563668d197c48caf2f23fcde9ec2ec101fe7
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24186
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2 files changed