package/ti-sgx-demos: new package

This package adds the SGX demos from Imagination Technologies, they are
available as binaries only.
This package contains binaries compiled for the SGX graphics accelerator used
in the following Texas Instruments SoCs: AM335x, AM437x, AM4430, AM5430.

Signed-off-by: Lothar Felten <lothar.felten@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>