LoongArch: modify defconfig according to other architectures

LoongArch inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6BWFP



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1. enable watdog support
2. enable some net class support, used by tc
3. use voluntary preemption
4. compile r8169 driver as m

Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>
Change-Id: I59315f265bfe54a00936b5c47aaa3c2e805d3ee6