s61x9_micoboard_defconfig: move to internal toolchain

Now that the xilinx external toolchains have been deprecated.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

configs/s6lx9_microboard_defconfig

@@ -1,11 +1,5 @@
 BR2_microblaze=y
 BR2_microblazeel=y
-BR2_TOOLCHAIN_EXTERNAL=y
-BR2_TOOLCHAIN_EXTERNAL_XILINX_MICROBLAZEEL_V2=y
-BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y
-BR2_TOOLCHAIN_EXTERNAL_CUSTOM_PREFIX="microblazeel-unknown-linux-gnu"
-BR2_TOOLCHAIN_EXTERNAL_CUSTOM_GLIBC=y
-BR2_TOOLCHAIN_EXTERNAL_CXX=y
 BR2_TARGET_GENERIC_GETTY_PORT="ttyUL0"
 # BR2_TARGET_ROOTFS_TAR is not set
 BR2_TARGET_ROOTFS_INITRAMFS=y