arch/powerpc: add ppc little endian openuler defconfig

hexin inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8T93I?from=project-issue


CVE: NA

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This defconfig's purpose to support openEuler compile ppc64le.
It is based on the redhat ppc64le config .

Signed-off-by: shenghui.qu <shenghui.qu@shingroup.cn>