refactor(stm32mp1): add helpers for IO compensation cells

Add enable_io_comp_cell and disable_io_comp_cell local helpers
to enable or disable an IO compensation cell.

Change-Id: I65295298a7ece572ae939e2db93d10b188de0f9e
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/plat/st/stm32mp1/include/stm32mp1_private.h b/plat/st/stm32mp1/include/stm32mp1_private.h
index 2eec16f..38de1b7 100644
--- a/plat/st/stm32mp1/include/stm32mp1_private.h
+++ b/plat/st/stm32mp1/include/stm32mp1_private.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2022, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -18,7 +18,8 @@
 void stm32mp1_gic_init(void);
 
 void stm32mp1_syscfg_init(void);
-void stm32mp1_syscfg_enable_io_compensation(void);
+void stm32mp1_syscfg_enable_io_compensation_start(void);
+void stm32mp1_syscfg_enable_io_compensation_finish(void);
 void stm32mp1_syscfg_disable_io_compensation(void);
 
 void stm32mp1_deconfigure_uart_pins(void);