MSCC: add board support for the Ocelots based evaluation boards

Adding the support for 2 boards sharing common code for Ocelot chip:
PCB120 and PCB123

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
diff --git a/configs/mscc_ocelot_defconfig b/configs/mscc_ocelot_defconfig
new file mode 100644
index 0000000..5fa74db
--- /dev/null
+++ b/configs/mscc_ocelot_defconfig
@@ -0,0 +1,67 @@
+CONFIG_MIPS=y
+CONFIG_SYS_TEXT_BASE=0x40000000
+CONFIG_SYS_MALLOC_F_LEN=0x2000
+CONFIG_DEBUG_UART_BOARD_INIT=y
+CONFIG_DEBUG_UART_BASE=0x70100000
+CONFIG_DEBUG_UART_CLOCK=250000000
+CONFIG_ARCH_MSCC=y
+CONFIG_TARGET_OCELOT_PCB123=y
+CONFIG_SYS_LITTLE_ENDIAN=y
+CONFIG_DEBUG_UART=y
+CONFIG_FIT=y
+CONFIG_BOOTDELAY=3
+CONFIG_USE_BOOTARGS=y
+CONFIG_BOOTARGS="console=ttyS0,115200"
+CONFIG_LOGLEVEL=7
+CONFIG_DISPLAY_CPUINFO=y
+CONFIG_SYS_PROMPT="pcb123 # "
+# CONFIG_CMD_BDI is not set
+# CONFIG_CMD_CONSOLE is not set
+# CONFIG_CMD_ELF is not set
+# CONFIG_CMD_EXPORTENV is not set
+# CONFIG_CMD_IMPORTENV is not set
+# CONFIG_CMD_CRC32 is not set
+CONFIG_CMD_MD5SUM=y
+CONFIG_CMD_MEMINFO=y
+CONFIG_CMD_MEMTEST=y
+# CONFIG_CMD_FLASH is not set
+CONFIG_CMD_GPIO=y
+CONFIG_CMD_MTD=y
+CONFIG_CMD_SF=y
+CONFIG_CMD_SPI=y
+CONFIG_CMD_DHCP=y
+# CONFIG_NET_TFTP_VARS is not set
+# CONFIG_CMD_NFS is not set
+CONFIG_CMD_PING=y
+CONFIG_CMD_MTDPARTS=y
+CONFIG_MTDIDS_DEFAULT="nor0=spi_flash"
+CONFIG_MTDPARTS_DEFAULT="mtdparts=spi_flash:512k(UBoot),256k(Env),256k(conf),15m(linux),15m(linux.bk)"
+CONFIG_CMD_UBI=y
+# CONFIG_CMD_UBIFS is not set
+# CONFIG_ISO_PARTITION is not set
+CONFIG_DEFAULT_DEVICE_TREE="ocelot_pcb123"
+CONFIG_ENV_IS_IN_SPI_FLASH=y
+CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_CLK=y
+CONFIG_DM_GPIO=y
+CONFIG_MTD=y
+CONFIG_MTD_SPI_NAND=y
+CONFIG_DM_SPI_FLASH=y
+CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_BAR=y
+CONFIG_SPI_FLASH_GIGADEVICE=y
+CONFIG_SPI_FLASH_MACRONIX=y
+CONFIG_SPI_FLASH_SPANSION=y
+CONFIG_SPI_FLASH_WINBOND=y
+CONFIG_SPI_FLASH_MTD=y
+CONFIG_DM_ETH=y
+CONFIG_PINCTRL=y
+CONFIG_PINCONF=y
+CONFIG_DM_SERIAL=y
+CONFIG_DEBUG_UART_SHIFT=2
+CONFIG_DEBUG_UART_ANNOUNCE=y
+CONFIG_SYS_NS16550=y
+CONFIG_SPI=y
+CONFIG_DM_SPI=y
+CONFIG_DESIGNWARE_SPI=y
+CONFIG_LZMA=y