cnss2: Fix an issue when MSM SSR feature is not enabled

Commit cd7f4158 ("cnss2: Wait for power up complete during
SSR restart") breaks the compilation when MSM SSR feature is
not enabled. Fix it properly in this change.

Change-Id: I9e16174a4063b037d50f890eccb0983bd68a54a8
Signed-off-by: Yue Ma <yuem@codeaurora.org>