buildroot: enable dhcpcd

buildroot-2021.05/configs/milkv_duo_musl_riscv64_defconfig

@@ -475,6 +475,7 @@ BR2_PACKAGE_STRACE=y
 # NetworkManager needs udev /dev management and a glibc toolchain w/ headers >= 3.2, dynamic library, wchar, threads
 #
 
+BR2_PACKAGE_DHCPCD=y
 BR2_PACKAGE_DNSMASQ=y
 BR2_PACKAGE_DROPBEAR=y
 BR2_PACKAGE_DROPBEAR_CLIENT=y

buildroot-2021.05/package/dhcpcd/0012-ignore-interface-usb0-for-duo.patch

+From 338ed2fb94a85df62285ab8b3358f4fde0da2ba3 Mon Sep 17 00:00:00 2001
+From: carbon <carbon@milkv.io>
+Date: Mon, 7 Aug 2023 11:00:44 +0800
+Subject: [PATCH] ignore interface usb0 for duo
+
+---
+ src/dhcpcd.conf | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/src/dhcpcd.conf b/src/dhcpcd.conf
+index 916e82d..a1441c5 100644
+--- a/src/dhcpcd.conf
++++ b/src/dhcpcd.conf
+@@ -46,3 +46,5 @@ require dhcp_server_identifier
+ #slaac hwaddr
+ # OR generate Stable Private IPv6 Addresses based from the DUID
+ slaac private
++
++denyinterfaces usb0
+-- 
+2.25.1
+