x86/apic: Invoke perf_events_lapic_init() after enabling APIC

If the APIC is soft disabled then unmasking an LVT entry does not work and
the write is ignored. perf_events_lapic_init() tries to do so.

Move the invocation after the point where the APIC has been enabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105218.962517234@linutronix.de