hikey960: enable File-Based Encryption

As FBE is required by Android 10 and higher.
The change here referenced documents here:
https://source.android.com/security/encryption/file-based

Test: ./android-vts/tools/vts-tradefed run vts-kernel -m VtsKernelEncryptionTest
    with android-mainline, android-5.4, android-hikey-linaro-4.19, android-hikey-linaro-4.14 kernels

Signed-off-by: Yongqin Liu <yongqin.liu@linaro.org>
Change-Id: Ic40d3fd55d6d10cf159e079e258e7deec4f0bf81
2 files changed