fix toolchain build, need to set -mcpu

target/config/Config.in.target

@@ -3,6 +3,7 @@
 
 config ADK_TARGET_CFLAGS
 	string
+	default "-mcpu=v7.10.d" if ADK_CPU_MICROBLAZE
 	default "-m4 -ml" if ADK_CPU_SH4 && ADK_little
 	default "-m4 -mb" if ADK_CPU_SH4 && ADK_big
 	default "-mcpu=powerpc" if ADK_CPU_PPC

target/microblaze/systems/qemu-microblaze

@@ -2,6 +2,7 @@ config ADK_TARGET_SYSTEM_QEMU_MICROBLAZE
 	bool "Qemu Emulator"
 	select ADK_microblaze
 	select ADK_qemu_microblaze
+	select ADK_CPU_MICROBLAZE
 	select ADK_TARGET_QEMU
 	select ADK_TARGET_KERNEL_LINUXBIN
 	help