powerpc/4xx: Constify cpm_suspend_ops

struct platform_suspend_ops are not supposed to change at runtime.
Functions suspend_set_ops working with const platform_suspend_ops. So
mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/4xx/cpm.c

@@ -240,7 +240,7 @@ static int cpm_suspend_enter(suspend_state_t state)
 	return 0;
 }
 
-static struct platform_suspend_ops cpm_suspend_ops = {
+static const struct platform_suspend_ops cpm_suspend_ops = {
 	.valid		= cpm_suspend_valid,
 	.enter		= cpm_suspend_enter,
 };