xtensa: reorganize irq flags tracing

entry.s only disables IRQs on hardware IRQ, move trace_hardirqs_off call
into do_interrupt. Check actual intlevel that will be restored on return
from exception handler to decide if trace_hardirqs_on should be called.
Annotate IRQ on/off points in the TIF_* handling loop on return from
exception handler.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

diff --cc arch/xtensa/kernel/entry.S
Simple merge

diff --cc arch/xtensa/kernel/traps.c
Simple merge