x86/config: Set CONFIG_TXGBE=m by default

driver inclusion
category: feature
bugzilla: 50777
CVE: NA

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Set CONFIG_TXGBE=m, so that its ko can be distributed in ISO on X86.

Signed-off-by: zhenpengzheng <zhenpengzheng@net-swift.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>