parisc: Replace cpu_up/down() with add/remove_cpu()

The core device API performs extra housekeeping bits that are missing
from directly calling cpu_up/down().

See commit a6717c0 ("powerpc/rtas: use device model APIs and
serialization during LPM") for an example description of what might go
wrong.

This also prepares to make cpu_up/down() a private interface of the CPU
subsystem.

Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://lkml.kernel.org/r/20200323135110.30522-13-qais.yousef@arm.com

arch/parisc/kernel/processor.c

@@ -212,7 +212,7 @@ static int __init processor_probe(struct parisc_device *dev)
 #ifdef CONFIG_SMP
 	if (cpuid) {
 		set_cpu_present(cpuid, true);
-		cpu_up(cpuid);
+		add_cpu(cpuid);
 	}
 #endif