clk: stm32mp: enable RTCAPB clock for dual-core chips

In order to correctly manage the bring-up of non boot CPUs, the RTCAPB
clock needs to be enabled.
It controls the access to backup registers, where the CPU entrypoint
will be stored.

Change-Id: Ifeeceb4faf64bc9e0778030444f437cc0bb27272
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>

drivers/st/clk/stm32mp1_clk.c

@@ -1912,9 +1912,18 @@ static void stm32mp1_osc_init(void)
 	}
 }
 
+static void sync_earlyboot_clocks_state(void)
+{
+	if (!stm32mp_is_single_core()) {
+		stm32mp1_clk_enable_secure(RTCAPB);
+	}
+}
+
 int stm32mp1_clk_probe(void)
 {
 	stm32mp1_osc_init();
 
+	sync_earlyboot_clocks_state();
+
 	return 0;
 }