tools: Set the tool's default binary name ...

This patch: fafd3ec9c assumes that tools must build from
the main makefile folder.
This assumption leads to the error when somebody wants to
build a tool from the tool's folder.
Hence changes are done to provide the default binary name
in the tool's makefile.

Change-Id: Iae570a7f8d322151376b6feb19e739300eecc3fc
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

tools: Get the tool's binary name from the main makefile ...

Currently, the tool's makefile override the tool's binary name
which is already been defined in the main makefile.
Hence fix is provided so that the tool's makefile get the tool's
binary name from the main makefile instead of overriding it.

Change-Id: I8af2bd391a96bba2dbcddef711338a94ebf5f038
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

tools: Add firmware authenticated encryption tool ...

Add firmware authenticated encryption tool which utilizes OpenSSL
library to encrypt firmwares using a key provided via cmdline. Currently
this tool supports AES-GCM as an authenticated encryption algorithm.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Change-Id: I60e296af1b98f1912a19d5f91066be7ea85836e4