stm32mp2: initial support

Add initial support for STM32MP2 SoCs family.

SoCs information are available here :
https://www.st.com/content/st_com/en/campaigns/microprocessor-stm32mp2.html

Migrate all MP1 related code into stm32mp1/ directory
Create stm32mp2 directory dedicated for STM32MP2 SoCs.

Common code to MP1, MP13 and MP25 is kept into
arch/arm/mach-stm32/mach-stm32mp directory :
  - boot_params.c
  - bsec
  - cmd_stm32key
  - cmd_stm32prog
  - dram_init.c
  - syscon.c
  - ecdsa_romapi.c

For STM32MP2, it also :
  - adds memory region description needed for ARMv8 MMU.
  - enables early data cache before relocation.
    During the transition before/after relocation, the MMU, initially setup
    at the beginning of DDR, must be setup again at a correct address after
    relocation. This is done in enables_caches() by disabling cache, force
    arch.tlb_fillptr to NULL which will force the MMU to be setup again but
    with a new value for gd->arch.tlb_addr. gd->arch.tlb_addr has been
    updated after relocation in arm_reserve_mmu().

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/arch/arm/mach-stm32mp/Makefile b/arch/arm/mach-stm32mp/Makefile
index a19b279..00dc25b 100644
--- a/arch/arm/mach-stm32mp/Makefile
+++ b/arch/arm/mach-stm32mp/Makefile
@@ -3,24 +3,17 @@
 # Copyright (C) 2018, STMicroelectronics - All Rights Reserved
 #
 
-obj-y += cpu.o
 obj-y += dram_init.o
 obj-y += syscon.o
 obj-y += bsec.o
 
-obj-$(CONFIG_STM32MP13x) += stm32mp13x.o
-obj-$(CONFIG_STM32MP15x) += stm32mp15x.o
+obj-$(CONFIG_STM32MP15x) += stm32mp1/
+obj-$(CONFIG_STM32MP13x) += stm32mp1/
+obj-$(CONFIG_STM32MP25X) += stm32mp2/
 
 obj-$(CONFIG_STM32_ECDSA_VERIFY) += ecdsa_romapi.o
-ifdef CONFIG_SPL_BUILD
-obj-y += spl.o
-obj-y += tzc400.o
-else
+ifndef CONFIG_SPL_BUILD
 obj-y += cmd_stm32prog/
 obj-$(CONFIG_CMD_STM32KEY) += cmd_stm32key.o
-obj-$(CONFIG_ARMV7_PSCI) += psci.o
 obj-$(CONFIG_TFABOOT) += boot_params.o
 endif
-
-obj-$(CONFIG_$(SPL_)STM32MP15_PWR) += pwr_regulator.o
-obj-$(CONFIG_OF_SYSTEM_SETUP) += fdt.o