x86: Add apic->x86_32_early_logical_apicid()

On x86_32, the mapping between cpu and logical apic ID differs
depending on the specific apic implementation in use.  The
mapping is initialized while bringing up CPUs; however, this
makes early inits ignore memory topology.

Add a x86_32 specific apic->x86_32_early_logical_apicid() which
is called early during boot to query the mapping.  The mapping
is later verified against the result of init_apic_ldr().  The
method is allowed to return BAD_APICID if it can't be determined
early.

noop variant which always returns BAD_APICID is implemented and
added to all x86_32 apic implementations.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: eric.dumazet@gmail.com
Cc: yinghai@kernel.org
Cc: brgerst@gmail.com
Cc: gorcunov@gmail.com
Cc: penberg@kernel.org
Cc: shaohui.zheng@intel.com
Cc: rientjes@google.com
LKML-Reference: <1295789862-25482-8-git-send-email-tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>