x86: clean up the APIC_DEST_LOGICAL logic

Impact: cleanup

The bigsmp and es7000 subarchitectures un-defined APIC_DEST_LOGICAL in
a rather nasty way by re-defining it to zero. That is infinitely
fragile and makes it very hard to see what to code really does in
a given context. The very same constant has different meanings and
values - depending on which subarch is enabled.

Untangle this mess by never undefining the constant, but instead
propagating the right values into the genapic driver templates.

Signed-off-by: Ingo Molnar <mingo@elte.hu>