Stop passing --gen_all_phony_targets to kati

https://github.com/google/kati/commit/6ff74ce8ee4a618060a5bc7dac408be909151518

should have made this workaround unnecessary. Now, even with
old build/core, "m -j32 PRODUCT-aosp_mips64-eng dist" does not
output a ninja file with "$(cat )".

Bug: 24384320
Change-Id: I262edf00dce39f39ec4e55d5ed7b1b6f8d931f33