arm/fvp-library: add recipe for the FVP Library

Add a recipe for the FVP Library:

https://developer.arm.com/tools-and-software/simulation-models/fixed-virtual-platforms



This is free to download but is behind a login-wall, and the FVPs are
license managed.

Change-Id: Ia0e7b1bfac54e06faf9d517d5b769acf9670724a
Signed-off-by: Ross Burton <ross.burton@arm.com>