armv8: enable HAFDBS for other ELx when FEAT_HAFDBS is present

u-boot could be run at EL1/EL2/EL3. so we set it as same as EL1 does.
otherwise it will hang when enable mmu, that is what we encounter
in our SOC.

Signed-off-by: meitao <meitaogao@asrmicro.com>
[ Paul: pick from the Android tree. Rebase to the upstream ]
Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Cc: Tom Rini <trini@konsulko.com>
Link: https://android.googlesource.com/platform/external/u-boot/+/3bf38943aeab4700c2319bff2a1477d99c6afd2f