ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_smp()

MCIP now registers it's own per cpu setup routine (for IPI IRQ request)
using smp_ops.init_irq_cpu().

So no need for platforms to do that. This now completely decouples
platforms from MCIP.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/plat-sim/platform.c

@@ -30,7 +30,4 @@ static const char *simulation_compat[] __initconst = {
 
 MACHINE_START(SIMULATION, "simulation")
 	.dt_compat	= simulation_compat,
-#ifdef CONFIG_ARC_MCIP
-	.init_smp	= mcip_init_smp,
-#endif
 MACHINE_END