CONF: put DEBUG and trace under flags

Global flags: ST_DEBUG_TRACE
if ST_DEBUG_TRACE = 1, the debug and trace are activated on all
boot stage
Specific boot stage debug and trace flags:
ST_CMD_LINE_DEBUG_TRACE: addons for remove trace on kernel
ST_UBOOT_DEBUG_TRACE: activate/deactivate silent mode on u-boot
ST_TF_A_DEBUG_TRACE: activate/deactivate trace and debug on TF-A
ST_OPTEE_DEBUG_TRACE: activate/deactivate trace and debug on optee

Change-Id: I09a0c528fcef18f466f0e2b7b46715e2e43c8cf8
Signed-off-by: Christophe Priouzeau <christophe.priouzeau@foss.st.com>

recipes-bsp/u-boot/u-boot-stm32mp/0098-silent_mode.patch

@@ -0,0 +1,24 @@
+From 2132a1ff883c92953e906ba8f32b13641bdb98c7 Mon Sep 17 00:00:00 2001
+From: Christophe Priouzeau <christophe.priouzeau@foss.st.com>
+Date: Fri, 16 Jul 2021 16:25:20 +0200
+Subject: [PATCH 12/12] cpr_silent
+
+---
+ include/configs/stm32mp1.h | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/include/configs/stm32mp1.h b/include/configs/stm32mp1.h
+index 72424abb8b..0088ced206 100644
+--- a/include/configs/stm32mp1.h
++++ b/include/configs/stm32mp1.h
+@@ -159,6 +159,7 @@
+ 	"env_check=if env info -p -d -q; then env save; fi\0" \
+ 	STM32MP_BOOTCMD \
+ 	BOOTENV \
++	"silent=1\0" \
+ 	"boot_net_usb_start=true\0"
+ 
+ #endif /* ifndef CONFIG_SPL_BUILD */
+-- 
+2.17.1
+