feat(st-clock): add STM32MP2 clock driver

This driver manages the clocks on STM32MP2 platforms.
It uses a dedicated RCC (Reset and Clock Control) peripheral.

Change-Id: I6ba2173e73222269a2dfca4c6897229276a150c0
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
diff --git a/plat/st/stm32mp2/platform.mk b/plat/st/stm32mp2/platform.mk
index 11b1138..d9969dd 100644
--- a/plat/st/stm32mp2/platform.mk
+++ b/plat/st/stm32mp2/platform.mk
@@ -53,6 +53,9 @@
 
 PLAT_BL_COMMON_SOURCES		+=	drivers/st/bsec/bsec3.c
 
+PLAT_BL_COMMON_SOURCES		+=	drivers/st/clk/clk-stm32-core.c				\
+					drivers/st/clk/clk-stm32mp2.c
+
 BL2_SOURCES			+=	plat/st/stm32mp2/plat_bl2_mem_params_desc.c
 BL2_SOURCES			+=	plat/st/stm32mp2/bl2_plat_setup.c