Revert "riscv64: re-enable an invoke fast path"

This reverts commit 301feae50e211656ec3ae1d0ac9445ca8bba623d.

Reason for revert: b/312482932 - breaks RISC-V boot.

Change-Id: Id5a506949abcb2bc85a10cf5efe9b65ac4ee8031
2 files changed