fdk-aac: Add fdk-aac-free for non BUILD_PATENTED configurations

fdk-aac: Add fdk-aac-free for non BUILD_PATENTED configurations

The core parts of AAC were patented back in 1998. Those patents have
expired.

Some of the newer AAC features involved with HE-AAC are still patented.
These patches are taken from fedora where they remove all patented
functionality.

Note that LC-AAC comprises the majority of AAC content. HE-AAC is for low
bitrate stuff like audiobooks.

Patches come from Fedora where this is also distributed.

Local compiles show a 40% size reduction in the final ipk.

Signed-off-by: Rosen Penev <rosenp@gmail.com>