icnss: Refactor QMI interface

WLAN host uses QMI as the transport to communicate the initial
control messages with WLAN firmware. Refactor the code such a
way that the transport can be ported to other interfaces.

Some of the data structures used by icnss for it's internal
operations are from the QMI generated code; remove all such
dependencies from QMI framework.

This change also makes sure that icnss driver can be compiled
even when QMI framework is not available.

Change-Id: Ib585a611b3dd42e96c810ddb54244bcdc4aaa47c
Signed-off-by: Sameer Thalappil <sameert@codeaurora.org>