nds32: default to 3.x kernel, tested on real hardware

target/linux/Config.in.kernelversion

@@ -22,7 +22,6 @@ default ADK_TARGET_LINUX_KERNEL_VERSION_4_9 if ADK_TARGET_ARCH_FRV
 default ADK_TARGET_LINUX_KERNEL_VERSION_4_9 if ADK_TARGET_SYSTEM_ST_STM32F429
 default ADK_TARGET_LINUX_KERNEL_VERSION_4_9 if ADK_TARGET_SYSTEM_ST_STM32F769
 default ADK_TARGET_LINUX_KERNEL_VERSION_5_4 if ADK_TARGET_ARCH_C6X
-default ADK_TARGET_LINUX_KERNEL_VERSION_5_15 if ADK_TARGET_ARCH_NDS32
 default ADK_TARGET_LINUX_KERNEL_VERSION_6_6 if ADK_TARGET_ARCH_IA64
 default ADK_TARGET_LINUX_KERNEL_VERSION_6_18
 
@@ -205,7 +204,6 @@ config ADK_TARGET_LINUX_KERNEL_VERSION_3_4
 	depends on !ADK_TARGET_ARCH_BFIN
 	depends on !ADK_TARGET_ARCH_CSKY
 	depends on !ADK_TARGET_ARCH_H8300
-	depends on !ADK_TARGET_ARCH_NDS32
 	depends on !ADK_TARGET_ARCH_NIOS2
 	depends on !ADK_TARGET_ARCH_OR1K
 	depends on !ADK_TARGET_ARCH_RISCV32