debugfs: regset32: make struct debugfs_reg32 pointer const

no user of that should ever change that pointer,
so let's mark it const to prevent that from
happening.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/debugfs.h

@@ -33,7 +33,7 @@ struct debugfs_reg32 {
 };
 
 struct debugfs_regset32 {
-	struct debugfs_reg32 *regs;
+	const struct debugfs_reg32 *regs;
 	int nregs;
 	void __iomem *base;
 };