ACPI: PM: s2idle: fix section mismatch warning

The acpi_sleep_suspend_setup() function is missing an __init annotation,
which causes a warning in rare configurations that end up not inlining
it into its caller:

WARNING: modpost: vmlinux.o: section mismatch in reference: acpi_sleep_suspend_setup (section: .text) -> acpi_s2idle_setup (section: .init.text)

It's only called from an __init function, so adding the annotation is
correct here.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/sleep.c

@@ -840,7 +840,7 @@ void __weak acpi_s2idle_setup(void)
 	s2idle_set_ops(&acpi_s2idle_ops);
 }
 
-static void acpi_sleep_suspend_setup(void)
+static void __init acpi_sleep_suspend_setup(void)
 {
 	bool suspend_ops_needed = false;
 	int i;