powerpc/configs: Drop unnecessary CONFIG_NUMA_BALANCING_DEFAULT_ENABLED

In commit 9654f95a ("powerpc: Enable NUMA balancing in
pseries[_le]_defconfig") we added CONFIG_NUMA_BALANCING_DEFAULT_ENABLED
to our defconfigs. But it's already enabled by default, so drop it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/configs/pseries_defconfig

@@ -17,7 +17,6 @@ CONFIG_IKCONFIG_PROC=y
 CONFIG_LOG_BUF_SHIFT=18
 CONFIG_LOG_CPU_MAX_BUF_SHIFT=13
 CONFIG_NUMA_BALANCING=y
-CONFIG_NUMA_BALANCING_DEFAULT_ENABLED=y
 CONFIG_CGROUPS=y
 CONFIG_MEMCG=y
 CONFIG_MEMCG_SWAP=y