icnss: Avoid wlan driver remove during modem graceful shutdown

In case of modem graceful shutdown case during wlan driver
remove it delete the wlan interface and later probe time
create the new interface. some time new interface may get
different interface index. Android wificond framework module
is not aware about this interface index change due to this
after recovery it try to do scan with old interface index
which result into scan failure.

To address above issue avoid wlan driver remove during modem
graceful shutdown.

CRs-Fixed: 2157835
Change-Id: I8b828bef8b5f43cc39ba8ee578dcafc6afaa98d6
Signed-off-by: Hardik Kantilal Patel <hkpatel@codeaurora.org>