stm32mp1: enable SYSCFG clock when disabling IO compensation

When going to low-power modes, the IO compensation is disabled through
the function stm32mp1_syscfg_disable_io_compensation(). But at this step,
the SYSCFG clock could be disabled. Enable it at the beginning of the
sequence.

Change-Id: I9e805cf5ca232f702963925a7d0d7d107dbb874d
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/tf-a/+/185955


Reviewed-by: CITOOLS <smet-aci-reviews@lists.codex.cro.st.com>
Reviewed-by: CIBUILD <smet-aci-builds@lists.codex.cro.st.com>

plat/st/stm32mp1/stm32mp1_syscfg.c

@@ -167,6 +167,8 @@ void stm32mp1_syscfg_disable_io_compensation(void)
 {
 	uint32_t value;
 
+	stm32mp1_clk_force_enable(SYSCFG);
+
 	/*
 	 * Deactivate automatic I/O compensation.
 	 * Warning: CSI is disabled automatically in STOP if not