cpu/hotplug: Remove disable_nonboot_cpus()

The single user could have called freeze_secondary_cpus() directly.

Since this function was a source of confusion, remove it as it's
just a pointless wrapper.

While at it, rename enable_nonboot_cpus() to thaw_secondary_cpus() to
preserve the naming symmetry.

Done automatically via:

	git grep -l enable_nonboot_cpus | xargs sed -i 's/enable_nonboot_cpus/thaw_secondary_cpus/g'

Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Link: https://lkml.kernel.org/r/20200430114004.17477-1-qais.yousef@arm.com

tools/power/pm-graph/sleepgraph.py

@@ -192,7 +192,7 @@ class SystemValues:
 		'suspend_console': {},
 		'acpi_pm_prepare': {},
 		'syscore_suspend': {},
-		'arch_enable_nonboot_cpus_end': {},
+		'arch_thaw_secondary_cpus_end': {},
 		'syscore_resume': {},
 		'acpi_pm_finish': {},
 		'resume_console': {},