Release v2.2.0

[mbanth]

• CHANGED: Made the FIR coefficient array that is used with the voice fixed factor of 3 up and down sampling functions usable from within C files as well as XC files.
• CHANGED: Aligned the FIR coefficient array to an 8-byte boundary. This ensures that the voice fixed factor of 3 up and down sampling functions do not crash with a LOAD_STORE exception.
• ADDED: Missing device attributes to the .xn file of the AN00231 app note.

[mbanth]

Closed by #68.