Revert "ANDROID: enable kernel crypto optimizations for RISC-V"

This reverts commit e2de1934 because the
clang version that's currently being used for bazel builds is slightly
too old for these options to be available.  We'll have to wait until
clang is upgraded to at least llvm-project commit 09058654f68d.

Bug: 332317531
Bug: 333840628
Change-Id: If9a21905cee39a79afbe24b42d941cb17c508c3b
Signed-off-by: Eric Biggers <ebiggers@google.com>