LoongArch: defconfig: enable CONFIG_CACHEFILES

LoongArch inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7362E



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enable cachefiles module, used by cachefilesd service.

Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>
Change-Id: I2c7a60b51e5c3a656b0821d6be9e505f1f9e6768