Add rules.mk for building Trusty.

(This is a no-op change for the Android build. The Android build system
doesn't care about rules.mk.)

This is cherry-picked from AOSP.  It's needed in mnc-dev so that the
t132-mnc branch of Trusty can track this version of BoringSSL rather
than the one from AOSP.  That's important so we can have reproducible
builds of the MNC version of Trusty for Volantis.

Bug: 22202624
Change-Id: I19359abd83983efa597047f88295bb4f88bb415b
1 file changed