lib: qmi: Introduce QMI Encode/Decode library

Introduce Encode/Decode Library to perform QMI message marshaling.
The QMI Encode/Decode Library encodes the kernel C data structures into
QMI wire format and decodes the messages in QMI wire format into kernel
C structures.

Change-Id: Ib443e697dafedeac8a790de9a3a8ed4a8444082f
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>