arm64: smp: Get ipi_raise tracepoint working again

'commit 741a8ec5 ("ARM64: smp: Prevent cluster LPM modes when
pending IPIs on cluster CPUs")' broke ipi_raise trace point. Get
it working again by replacing __smp_cross_call() with smp_cross_call(),
which has a call to ipi_raise() tracepoint.

While at it, add missing update to pending_ipi flag for IPI_IRQ_WORK.

Change-Id: I4a847e833bf3b21abc58be88dfdc45da9bcfc676
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>