riscv: canaan: k230_canmv: Add initial support

Add support for K230 CanMV board with serial console and usb otg
support. It can boot via vendor's u-boot-spl and boot into Linux
via tftp through the onboard RTL8152.

Signed-off-by: Junhui Liu <junhui.liu@pigmoral.tech>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>

board/canaan/k230_canmv/Kconfig

@@ -0,0 +1,19 @@
+if TARGET_K230_CANMV
+
+config SYS_BOARD
+	default "k230_canmv"
+
+config SYS_VENDOR
+	default "canaan"
+
+config SYS_CPU
+	default "k230"
+
+config TEXT_BASE
+	default 0x0
+
+config BOARD_SPECIFIC_OPTIONS
+	def_bool y
+	select CANAAN_K230
+
+endif

board/canaan/k230_canmv/MAINTAINERS

@@ -0,0 +1,6 @@
+K230 CANMV
+M:	Junhui Liu <junhui.liu@pigmoral.tech>
+S:	Maintained
+F:	board/canaan/k230_canmv/
+F:	configs/k230_canmv_defconfig
+F:	doc/board/canaan/k230_canmv.rst

board/canaan/k230_canmv/Makefile

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) 2025, Junhui Liu <junhui.liu@pigmoral.tech>
+
+obj-y += board.o

board/canaan/k230_canmv/board.c

@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2025, Junhui Liu <junhui.liu@pigmoral.tech>
+ */
+
+int board_init(void)
+{
+	return 0;
+}

configs/k230_canmv_defconfig

@@ -0,0 +1,19 @@
+CONFIG_RISCV=y
+CONFIG_SYS_MALLOC_F_LEN=0x40000
+CONFIG_NR_DRAM_BANKS=1
+CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
+CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x80400000
+CONFIG_DEFAULT_DEVICE_TREE="k230-canmv"
+CONFIG_SYS_LOAD_ADDR=0xc000000
+CONFIG_TARGET_K230_CANMV=y
+CONFIG_ARCH_RV64I=y
+CONFIG_HUSH_PARSER=y
+CONFIG_SYS_PROMPT="K230# "
+CONFIG_CMD_USB=y
+CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_SYS_NS16550=y
+CONFIG_SYS_NS16550_MEM32=y
+CONFIG_USB=y
+CONFIG_USB_DWC2=y
+CONFIG_USB_HOST_ETHER=y
+CONFIG_USB_ETHER_RTL8152=y