Makefile: Ignore known_hosts for ssh and scp in makefile

The original ssh and scp commands in the Makefile for install relied on
the Chameleon's IP already being in the list of ~/.ssh/known_hosts.
These flags will ignore the existing known hosts so and not to fail on
make install.

BUG=b:69863789
TEST=Setup a new Chameleon from scratch without error.

Change-Id: Ibf74c293adde90a4849789f270b573d4ae919852
Reviewed-on: https://chromium-review.googlesource.com/794950
Commit-Ready: Alec Thilenius <athilenius@chromium.org>
Tested-by: Alec Thilenius <athilenius@chromium.org>
Reviewed-by: Wai-Hong Tam <waihong@google.com>
1 file changed