openeuler_defconfig: enable erofs ondemand for x86 and arm64

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8RP48



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To support erofs over fscache mode, the following config is enabled by
default on x86 and arm64:

	CONFIG_CACHEFILES_ONDEMAND=y
	CONFIG_EROFS_FS=m
	CONFIG_EROFS_FS_XATTR=y
	CONFIG_EROFS_FS_POSIX_ACL=y
	CONFIG_EROFS_FS_SECURITY=y
	CONFIG_EROFS_FS_ONDEMAND=y

Signed-off-by: Baokun Li <libaokun1@huawei.com>