feat(console): introduce EARLY_CONSOLE

This is a generic porting of what was done on ST platforms with flag
STM32MP_EARLY_CONSOLE. It creates the flag and the prototype for
plat_setup_early_console(). This function depends on platform
implementation. This function call is added at the beginning of each BL
image early setup function.
The patch also introduce an extra log macro: EARLY_ERROR. This can
replace ERROR macro in code that will only be executed before the
default console is enabled, and will do nothing when the EARLY_CONSOLE
is not enabled. This can then save some space in memory.

Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: I77bf0a0c4289b4c7df94e4bfb783a938e05bf023
diff --git a/bl1/bl1_main.c b/bl1/bl1_main.c
index 6fe5511..657366b 100644
--- a/bl1/bl1_main.c
+++ b/bl1/bl1_main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2023, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -64,6 +64,9 @@
  ******************************************************************************/
 void bl1_setup(void)
 {
+	/* Enable early console if EARLY_CONSOLE flag is enabled */
+	plat_setup_early_console();
+
 	/* Perform early platform-specific setup */
 	bl1_early_platform_setup();