feat(stm32mp2): add BL31 device tree support

BL31 will need to access a device tree for several configurations (UART,
GIC, OTP mapping...).
Create a BL31 device tree (SOC_FW_CONFIG). It is loaded in DDR, in a
spare area.

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Signed-off-by: Maxime Méré <maxime.mere@foss.st.com>
Change-Id: I320a05859e1aa3dd8db9a274e7201075a8c250c2
diff --git a/plat/st/stm32mp2/stm32mp2_def.h b/plat/st/stm32mp2/stm32mp2_def.h
index 73116db..b441502 100644
--- a/plat/st/stm32mp2/stm32mp2_def.h
+++ b/plat/st/stm32mp2/stm32mp2_def.h
@@ -138,7 +138,11 @@
  * MAX_MMAP_REGIONS is usually:
  * BL stm32mp2_mmap size + mmap regions in *_plat_arch_setup
  */
+#if defined(IMAGE_BL31)
+#define MAX_MMAP_REGIONS			7
+#else
 #define MAX_MMAP_REGIONS			6
+#endif
 
 /* DTB initialization value */
 #define STM32MP_BL2_DTB_SIZE			U(0x00006000)	/* 24 KB for DTB */
@@ -166,6 +170,7 @@
 #define STM32MP_HW_CONFIG_BASE			(STM32MP_BL33_BASE + \
 						STM32MP_BL33_MAX_SIZE)
 #define STM32MP_HW_CONFIG_MAX_SIZE		U(0x40000)
+#define STM32MP_SOC_FW_CONFIG_MAX_SIZE		U(0x10000) /* 64kB for BL31 DT */
 
 /*******************************************************************************
  * STM32MP2 device/io map related constants (used for MMU)