ARM: Kirkwood: fix kirkwood_pm_init() declaration/type

The kirkwood-pm.c was missing the include of kirkwood-pm.h to
define the kirkwood_pm_init() function. However once this is
included, the types do not match.

Fixup the include, and then the prototype to avoid the following
warning:

arch/arm/mach-mvebu/kirkwood-pm.c:69:12: warning: symbol 'kirkwood_pm_init' was not declared. Should it be static?

Signed-off-by: Ben Dooks <[e-mail]>
Reviewed-by: Andrew Lunn <[e-mail]>
Signed-off-by: Gregory CLEMENT <[e-mail]>

arch/arm/mach-mvebu/kirkwood-pm.c

···
 #include <linux/suspend.h>
 #include <linux/io.h>
 #include "kirkwood.h"
+#include "kirkwood-pm.h"
 
 static void __iomem *ddr_operation_base;
 static void __iomem *memory_pm_ctrl;
···
 	.valid = kirkwood_pm_valid_standby,
 };
 
-int __init kirkwood_pm_init(void)
+void __init kirkwood_pm_init(void)
 {
 	ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4);
 	memory_pm_ctrl = ioremap(MEMORY_PM_CTRL_PHYS, 4);
 
 	suspend_set_ops(&kirkwood_suspend_ops);
-	return 0;
 }