This is the first commit containing helper makefiles to be able to build
OP-TEE easily regardless of previous knowledge of OP-TEE.

To use this particular git and the makefiles, you should have installed
the environment according to the instructions at:
  https://github.com/OP-TEE/manifest/blob/master/README.md



In this commit there are support for building OP-TEE for:
 - QEMU (default)
 - FVP
 - Hikey

More targets will be added later on.

Signed-off-by: Joakim Bech <joakim.bech@linaro.org>
Tested-by: Joakim Bech <joakim.bech@linaro.org> (QEMU, FVP)
Tested-by: Victor Chong <victor.chong@linaro.org> (Hikey)