clk: spacemit: fix comment typo

Fix incorrect comment to match the filename.

Reviewd-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
Signed-off-by: Encrow Thorne <jyc0019@gmail.com>
Reviewed-by: Yixun Lan <dlan@gentoo.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: EncrowThorne19

drivers/clk/spacemit/ccu_mix.h

@@ -220,4 +220,4 @@ extern const struct clk_ops spacemit_ccu_div_gate_ops;
 extern const struct clk_ops spacemit_ccu_mux_gate_ops;
 extern const struct clk_ops spacemit_ccu_mux_div_ops;
 extern const struct clk_ops spacemit_ccu_mux_div_gate_ops;
-#endif /* _CCU_DIV_H_ */
+#endif /* _CCU_MIX_H_ */