ANDROID: hikey960: Fix up HiKey960 build with symbol strict mode

After commit 205d5f73 ("ANDROID: GKI: Enable symbol trimming
and strict mode"), HiKey960 stopped booting properly.

Will McVicker suggested we add a new symbol list:
  android/abi_gki_aarch64_hikey960

So this patch does this. However, we also ran into an issue with
one of the configs we had enabled needing filp_open() which is
no longer allowed. So this patch also disables
CONFIG_NVME_TARGET (which wasn't really necessary) to avoid
this.

Fixes: 205d5f73 ("ANDROID: GKI: Enable symbol trimming and strict mode")
Signed-off-by: John Stultz <john.stultz@linaro.org>
Change-Id: I3b7a862805f134f1dfa49e2a0c2e47ee5bb3b83a