stm32mp1: update clock driver

Remove useless private structure in function prototypes.
Add a reference counter on clocks.
Prepare for future secured/shared/non-secured clocks.

Change-Id: I3dbed81721da5ceff5e10b2c4155b1e340c036ee
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Nicolas LE BAYON <nicolas.le.bayon@st.com>
diff --git a/plat/st/common/include/stm32mp_common.h b/plat/st/common/include/stm32mp_common.h
index fa0b630..4bbc4db 100644
--- a/plat/st/common/include/stm32mp_common.h
+++ b/plat/st/common/include/stm32mp_common.h
@@ -50,8 +50,8 @@
  * @id: Target clock ID, ID used in clock DT bindings
  */
 bool stm32mp_clk_is_enabled(unsigned long id);
-int stm32mp_clk_enable(unsigned long id);
-int stm32mp_clk_disable(unsigned long id);
+void stm32mp_clk_enable(unsigned long id);
+void stm32mp_clk_disable(unsigned long id);
 unsigned long stm32mp_clk_get_rate(unsigned long id);
 
 /* Initialise the IO layer and register platform IO devices */