stm32mp1: ram: remove tuning support

Remove the DDR interactive command tuning, as the support of a predefined
DDR PHY tuning is removed for STM32MP1 driver in SPL and in TF-A
and the result of this tuning will be never used.

Moreover this SW tuning procedure can failed on some hardware
configuration (to many BIST errors and no convergence); it will be no
more supported in the next delivery of the DDR utilities included in
the CubeMX tool of STMicroelectronics.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/drivers/ram/stm32mp1/stm32mp1_ddr.c b/drivers/ram/stm32mp1/stm32mp1_ddr.c
index 9d08660..4d78aa5 100644
--- a/drivers/ram/stm32mp1/stm32mp1_ddr.c
+++ b/drivers/ram/stm32mp1/stm32mp1_ddr.c
@@ -557,7 +557,7 @@
 		  (u32)&phy->pgsr, pgsr, ret);
 }
 
-void stm32mp1_ddrphy_init(struct stm32mp1_ddrphy *phy, u32 pir)
+static void stm32mp1_ddrphy_init(struct stm32mp1_ddrphy *phy, u32 pir)
 {
 	pir |= DDRPHYC_PIR_INIT;
 	writel(pir, &phy->pir);
@@ -626,7 +626,7 @@
 	log_debug("[0x%08x] stat = 0x%08x\n", (u32)&priv->ctl->stat, stat);
 }
 
-void stm32mp1_refresh_disable(struct stm32mp1_ddrctl *ctl)
+static void stm32mp1_refresh_disable(struct stm32mp1_ddrctl *ctl)
 {
 	start_sw_done(ctl);
 	/* quasi-dynamic register update*/
@@ -637,8 +637,8 @@
 	wait_sw_done_ack(ctl);
 }
 
-void stm32mp1_refresh_restore(struct stm32mp1_ddrctl *ctl,
-			      u32 rfshctl3, u32 pwrctl)
+static void stm32mp1_refresh_restore(struct stm32mp1_ddrctl *ctl,
+				     u32 rfshctl3, u32 pwrctl)
 {
 	start_sw_done(ctl);
 	if (!(rfshctl3 & DDRCTRL_RFSHCTL3_DIS_AUTO_REFRESH))