cnss2: Do sync resume during driver shutdown

Since driver shutdown is in work context, it is safe to do sync
resume for runtime PM to avoid race condition. Add the missing
resume request support to runtime PM debugfs node as well.

Change-Id: Ia1e072bcfbfc62e189d9d1f9119c53bbefc9c8ef
Signed-off-by: Yue Ma <yuem@codeaurora.org>