Update Kconfig.

1. Add IPADDR/GWADDR etc;
2. Add Kconfig for libcpu.

KConfig

 source "$RTT_DIR/src/KConfig"
+source "$RTT_DIR/libcpu/Kconfig"
 source "$RTT_DIR/components/KConfig"

components/net/KConfig

@@ -55,6 +55,20 @@ config RT_USING_LWIP
                     default n
             endif
 
+            if !RT_LWIP_DHCP
+                config RT_LWIP_IPADDR
+                    string "IPv4: IP address"
+                    default 192.168.1.30
+
+                config RT_LWIP_GWADDR
+                    string "IPv4: Gateway address"
+                    default 192.168.1.1
+                
+                config RT_LWIP_MSKADDR
+                    string "IPv4: Mask address"
+                    default 255.255.255.0
+            endif
+
         config RT_LWIP_UDP
             bool "UDP protocol"
             default y

libcpu/Kconfig

+config ARCH_ARM
+    bool
+
+config ARCH_ARM_CORTEX_M
+    bool
+    select ARCH_ARM
+
+config ARCH_ARM_CORTEX_M0
+    bool
+    select ARCH_ARM_CORTEX_M
+
+config ARCH_ARM_CORTEX_M3
+    bool
+    select ARCH_ARM_CORTEX_M
+
+config ARCH_ARM_MPU
+    bool
+    depends on ARCH_ARM
+
+config ARCH_ARM_CORTEX_M4
+    bool
+    select ARCH_ARM_CORTEX_M
+
+config ARCH_ARM_CORTEX_M7
+    bool
+    select ARCH_ARM_CORTEX_M
+
+config ARCH_ARM_CORTEX_R
+    bool
+    select ARCH_ARM
+
+config ARCH_ARM_MMU
+    bool
+    depends on ARCH_ARM
+
+config ARCH_ARM_CORTEX_A5
+    bool
+    select ARCH_ARM
+
+config ARCH_ARM_CORTEX_A7
+    bool
+    select ARCH_ARM
+
+config ARCH_ARM_CORTEX_A8
+    bool
+    select ARCH_ARM
+
+config ARCH_ARM_CORTEX_A9
+    bool
+    select ARCH_ARM
+
+config ARCH_MIPS
+    bool
+
+config ARCH_MIPS_XBURST
+    bool
+    select ARCH_MIPS
+
+config ARCH_ANDES
+    bool
+
+config ARCH_CSKY
+    bool
+
+config ARCH_POWERPC
+    bool
+
+config ARCH_RISCV
+    bool
+
+config ARCH_IA32
+    bool
+
+config ARCH_HOST_SIMULATOR
+    bool