powerpc/wii: Fix declaration made after definition

A 0day randconfig uncovered an error with clang, trimmed for brevity:

arch/powerpc/platforms/embedded6xx/wii.c:195:7: error: attribute
declaration must precede definition [-Werror,-Wignored-attributes]
        if (!machine_is(wii))
             ^

The macro machine_is declares mach_##name but define_machine actually
defines mach_##name, hence the warning.

To fix this, move define_machine after the is_machine usage.

Fixes: 5a7ee3198d ("powerpc: wii: platform support")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/989
Link: https://lore.kernel.org/r/20200413190644.16757-1-natechancellor@gmail.com

arch/powerpc/platforms/embedded6xx/wii.c

@@ -172,19 +172,6 @@ static void wii_shutdown(void)
 	flipper_quiesce();
 }
 
-define_machine(wii) {
-	.name			= "wii",
-	.probe			= wii_probe,
-	.setup_arch		= wii_setup_arch,
-	.restart		= wii_restart,
-	.halt			= wii_halt,
-	.init_IRQ		= wii_pic_probe,
-	.get_irq		= flipper_pic_get_irq,
-	.calibrate_decr		= generic_calibrate_decr,
-	.progress		= udbg_progress,
-	.machine_shutdown	= wii_shutdown,
-};
-
 static const struct of_device_id wii_of_bus[] = {
 	{ .compatible = "nintendo,hollywood", },
 	{ },
@@ -200,3 +187,15 @@ static int __init wii_device_probe(void)
 }
 device_initcall(wii_device_probe);
 
+define_machine(wii) {
+	.name			= "wii",
+	.probe			= wii_probe,
+	.setup_arch		= wii_setup_arch,
+	.restart		= wii_restart,
+	.halt			= wii_halt,
+	.init_IRQ		= wii_pic_probe,
+	.get_irq		= flipper_pic_get_irq,
+	.calibrate_decr		= generic_calibrate_decr,
+	.progress		= udbg_progress,
+	.machine_shutdown	= wii_shutdown,
+};