powerpc/smp: Use IS_ENABLED() to avoid #ifdef

We can avoid the #ifdef by using IS_ENABLED() in the existing
condition check.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313112020.28235-2-mpe@ellerman.id.au

arch/powerpc/kernel/smp.c

@@ -1189,18 +1189,17 @@ int get_physical_package_id(int cpu)
 {
 	int pkg_id = cpu_to_chip_id(cpu);
 
-#ifdef CONFIG_PPC_SPLPAR
 	/*
 	 * If the platform is PowerNV or Guest on KVM, ibm,chip-id is
 	 * defined. Hence we would return the chip-id as the result of
 	 * get_physical_package_id.
 	 */
-	if (pkg_id == -1 && firmware_has_feature(FW_FEATURE_LPAR)) {
+	if (pkg_id == -1 && firmware_has_feature(FW_FEATURE_LPAR) &&
+	    IS_ENABLED(CONFIG_PPC_SPLPAR)) {
 		struct device_node *np = of_get_cpu_node(cpu, NULL);
 		pkg_id = of_node_to_nid(np);
 		of_node_put(np);
 	}
-#endif /* CONFIG_PPC_SPLPAR */
 
 	return pkg_id;
 }