fix(st-clock): disabling CKPER clock is not functional on stm32mp13

The mask used to configure the CKPER MUX was wrong and unnecessary.

Change-Id: I40098f2a27b9e5ba8706ab5377d23f578c09838b
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
diff --git a/drivers/st/clk/clk-stm32mp13.c b/drivers/st/clk/clk-stm32mp13.c
index db427ad..01d1764 100644
--- a/drivers/st/clk/clk-stm32mp13.c
+++ b/drivers/st/clk/clk-stm32mp13.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2022, STMicroelectronics - All Rights Reserved
+ * Copyright (C) 2022-2023, STMicroelectronics - All Rights Reserved
  *
  * SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
  */
@@ -1216,7 +1216,7 @@
 	 * => deactivate CKPER only after switching clock
 	 */
 	if (ckper_disabled) {
-		ret = stm32_clk_configure_mux(priv, CLK_CKPER_DISABLED & CMD_MASK);
+		ret = stm32_clk_configure_mux(priv, CLK_CKPER_DISABLED);
 		if (ret != 0) {
 			return ret;
 		}