cpu-topology: declare parse_acpi_topology in <linux/arch_topology.h>

The parse_acpi_topology() is not declared anywhere which
causes the following sparse warning:

drivers/base/arch_topology.c:522:19: warning: symbol 'parse_acpi_topology' was not declared. Should it be static?
Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20191022084323.13594-1-ben.dooks@codethink.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/arch_topology.h

@@ -57,6 +57,7 @@ const struct cpumask *cpu_coregroup_mask(int cpu);
 void update_siblings_masks(unsigned int cpu);
 void remove_cpu_topology(unsigned int cpuid);
 void reset_cpu_topology(void);
+int parse_acpi_topology(void);
 #endif
 
 #endif /* _LINUX_ARCH_TOPOLOGY_H_ */