cnss2: Avoid suspending PCIe after QMI send get is called

Introduce usage count for QMI send get/put APIs. Make sure PCIe link
will not be suspended from runtime PM path if the usage count is not 0.
That means PCIe link should be always up when host driver starts to
proceed stats query from upper layer.

Change-Id: I0ff62874d62c4db2292236d8b4b5c2e09e439a5b
Signed-off-by: Yue Ma <yuem@codeaurora.org>