board: siemens: iot2050: Split the build for PG1 and PG2

Due to different signature keys, the PG1 and the PG2 boards can no
longer use the same FSBL (tiboot3). This makes it impossible anyway to
maintaine a single flash.bin for both variants, so we can also split the
build.

A new target is added to indicates the build is for PG1 vs. PG2 boards.
Hence now the variants have separated defconfig files.

The runtime board_is_sr1() check does make no sense anymore, so remove
it and replace with build time check.

Documentation is updated accordingly. New binary artifacts are already
available via meta-iot2050.

Signed-off-by: Su Baocheng <baocheng.su@siemens.com>
[Jan: refactor config option into targets, tweak some wordings]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
diff --git a/configs/iot2050_pg2_defconfig b/configs/iot2050_pg2_defconfig
new file mode 100644
index 0000000..58aefac
--- /dev/null
+++ b/configs/iot2050_pg2_defconfig
@@ -0,0 +1,149 @@
+CONFIG_ARM=y
+CONFIG_SKIP_LOWLEVEL_INIT=y
+CONFIG_ARCH_K3=y
+CONFIG_SYS_MALLOC_LEN=0x2000000
+CONFIG_SYS_MALLOC_F_LEN=0x8000
+CONFIG_SPL_GPIO=y
+CONFIG_SPL_LIBCOMMON_SUPPORT=y
+CONFIG_SPL_LIBGENERIC_SUPPORT=y
+CONFIG_NR_DRAM_BANKS=2
+CONFIG_SOC_K3_AM654=y
+CONFIG_TARGET_IOT2050_A53_PG2=y
+CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
+CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x80100000
+CONFIG_ENV_SIZE=0x20000
+CONFIG_ENV_OFFSET=0x680000
+CONFIG_ENV_SECT_SIZE=0x20000
+CONFIG_DM_GPIO=y
+CONFIG_SPL_DM_SPI=y
+CONFIG_DEFAULT_DEVICE_TREE="k3-am6528-iot2050-basic-pg2"
+CONFIG_SPL_TEXT_BASE=0x80080000
+CONFIG_SYS_PROMPT="IOT2050> "
+CONFIG_SPL_SERIAL=y
+CONFIG_SPL_STACK_R_ADDR=0x82000000
+CONFIG_ENV_OFFSET_REDUND=0x6a0000
+CONFIG_SPL_SPI_FLASH_SUPPORT=y
+CONFIG_SPL_SPI=y
+CONFIG_DISTRO_DEFAULTS=y
+CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
+CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x80100000
+# CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
+CONFIG_SPL_LOAD_FIT=y
+# CONFIG_USE_SPL_FIT_GENERATOR is not set
+CONFIG_OF_BOARD_SETUP=y
+CONFIG_BOOTSTAGE=y
+CONFIG_SHOW_BOOT_PROGRESS=y
+CONFIG_SPL_SHOW_BOOT_PROGRESS=y
+CONFIG_CONSOLE_MUX=y
+# CONFIG_DISPLAY_CPUINFO is not set
+CONFIG_SPL_MAX_SIZE=0x58000
+CONFIG_SPL_HAS_BSS_LINKER_SECTION=y
+CONFIG_SPL_BSS_START_ADDR=0x80a00000
+CONFIG_SPL_BSS_MAX_SIZE=0x80000
+CONFIG_SPL_BOARD_INIT=y
+CONFIG_SPL_SYS_MALLOC_SIMPLE=y
+CONFIG_SPL_STACK_R=y
+CONFIG_SYS_SPL_MALLOC=y
+CONFIG_SYS_SPL_MALLOC_SIZE=0x800000
+CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR=y
+CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR=0x1400
+CONFIG_SPL_DM_MAILBOX=y
+CONFIG_SPL_DM_SPI_FLASH=y
+CONFIG_SPL_DM_RESET=y
+CONFIG_SPL_POWER_DOMAIN=y
+# CONFIG_SPL_SPI_FLASH_TINY is not set
+CONFIG_SPL_SPI_FLASH_SFDP_SUPPORT=y
+CONFIG_SPL_SPI_LOAD=y
+CONFIG_SYS_SPI_U_BOOT_OFFS=0x280000
+CONFIG_SYS_MAXARGS=64
+CONFIG_SYS_PBSIZE=1050
+CONFIG_CMD_ASKENV=y
+CONFIG_CMD_DFU=y
+CONFIG_CMD_GPT=y
+CONFIG_CMD_I2C=y
+CONFIG_CMD_MMC=y
+CONFIG_CMD_PCI=y
+CONFIG_CMD_REMOTEPROC=y
+CONFIG_CMD_USB=y
+CONFIG_CMD_WDT=y
+# CONFIG_CMD_SETEXPR is not set
+CONFIG_CMD_TIME=y
+# CONFIG_ISO_PARTITION is not set
+CONFIG_OF_CONTROL=y
+CONFIG_SPL_OF_CONTROL=y
+CONFIG_SPL_MULTI_DTB_FIT=y
+CONFIG_SPL_OF_LIST="k3-am65-iot2050-spl"
+CONFIG_SPL_MULTI_DTB_FIT_NO_COMPRESSION=y
+CONFIG_ENV_IS_IN_SPI_FLASH=y
+CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
+CONFIG_DM=y
+CONFIG_SPL_DM=y
+CONFIG_SPL_DM_SEQ_ALIAS=y
+CONFIG_SPL_REGMAP=y
+CONFIG_SPL_OF_TRANSLATE=y
+CONFIG_CLK=y
+CONFIG_SPL_CLK=y
+CONFIG_CLK_TI_SCI=y
+CONFIG_DFU_MMC=y
+CONFIG_DFU_RAM=y
+CONFIG_DFU_SF=y
+CONFIG_DMA_CHANNELS=y
+CONFIG_TI_K3_NAVSS_UDMA=y
+CONFIG_TI_SCI_PROTOCOL=y
+CONFIG_DA8XX_GPIO=y
+CONFIG_DM_PCA953X=y
+CONFIG_DM_I2C=y
+CONFIG_I2C_SET_DEFAULT_BUS_NUM=y
+CONFIG_SYS_I2C_OMAP24XX=y
+CONFIG_LED=y
+CONFIG_SPL_LED=y
+CONFIG_LED_GPIO=y
+CONFIG_SPL_LED_GPIO=y
+CONFIG_DM_MAILBOX=y
+CONFIG_K3_SEC_PROXY=y
+CONFIG_MMC_HS200_SUPPORT=y
+CONFIG_MMC_SDHCI=y
+CONFIG_MMC_SDHCI_ADMA=y
+CONFIG_MMC_SDHCI_AM654=y
+CONFIG_DM_SPI_FLASH=y
+CONFIG_SPI_FLASH_SFDP_SUPPORT=y
+CONFIG_SPI_FLASH_STMICRO=y
+CONFIG_SPI_FLASH_WINBOND=y
+# CONFIG_SPI_FLASH_USE_4K_SECTORS is not set
+CONFIG_PCI=y
+CONFIG_PCI_KEYSTONE=y
+CONFIG_PHY=y
+CONFIG_AM654_PHY=y
+CONFIG_OMAP_USB2_PHY=y
+CONFIG_PINCTRL=y
+# CONFIG_PINCTRL_GENERIC is not set
+CONFIG_SPL_PINCTRL=y
+# CONFIG_SPL_PINCTRL_GENERIC is not set
+CONFIG_PINCTRL_SINGLE=y
+CONFIG_POWER_DOMAIN=y
+CONFIG_TI_SCI_POWER_DOMAIN=y
+CONFIG_REMOTEPROC_TI_K3_R5F=y
+CONFIG_DM_RESET=y
+CONFIG_RESET_TI_SCI=y
+CONFIG_DM_SERIAL=y
+CONFIG_SOC_DEVICE=y
+CONFIG_SOC_DEVICE_TI_K3=y
+CONFIG_SOC_TI=y
+CONFIG_SPI=y
+CONFIG_DM_SPI=y
+CONFIG_CADENCE_QSPI=y
+CONFIG_SYSRESET=y
+CONFIG_SPL_SYSRESET=y
+CONFIG_SYSRESET_TI_SCI=y
+CONFIG_USB=y
+CONFIG_USB_XHCI_HCD=y
+CONFIG_USB_XHCI_DWC3=y
+CONFIG_USB_DWC3=y
+CONFIG_USB_DWC3_GENERIC=y
+CONFIG_USB_KEYBOARD=y
+# CONFIG_WATCHDOG is not set
+# CONFIG_WATCHDOG_AUTOSTART is not set
+CONFIG_WDT=y
+CONFIG_WDT_K3_RTI=y
+CONFIG_WDT_K3_RTI_LOAD_FW=y
+CONFIG_OF_LIBFDT_OVERLAY=y