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/drivers/st/ddr/stm32mp1_ddr_helpers.c b/drivers/st/ddr/stm32mp1_ddr_helpers.c
index c66c9e7..fcb4cfc 100644
--- a/drivers/st/ddr/stm32mp1_ddr_helpers.c
+++ b/drivers/st/ddr/stm32mp1_ddr_helpers.c
@@ -11,10 +11,14 @@
 
 void ddr_enable_clock(void)
 {
+	stm32mp1_clk_rcc_regs_lock();
+
 	mmio_setbits_32(stm32mp_rcc_base() + RCC_DDRITFCR,
 			RCC_DDRITFCR_DDRC1EN |
 			RCC_DDRITFCR_DDRC2EN |
 			RCC_DDRITFCR_DDRPHYCEN |
 			RCC_DDRITFCR_DDRPHYCAPBEN |
 			RCC_DDRITFCR_DDRCAPBEN);
+
+	stm32mp1_clk_rcc_regs_unlock();
 }