qcacld-3.0: Use PM wakelock to protect firmware downloading

To protect firmware not downloaded in system suspend, acquire/release
the cnss semaphore cnss_pm_sem. It is complex, and cnss function
cnss_pm_notify may trigger dead lock issue once PM_POST_SUSPEND is
ahead of PM_SUSPEND_PREPARE.

Optimize code to use PM wakelock API to protect firmware downloading.

Change-Id: I533c373b85f554fbcceb562d9f56c6b88e5155bb
CRs-Fixed: 3280247

core/pld/inc/pld_common.h

@@ -854,8 +854,6 @@ int pld_get_mhi_state(struct device *dev);
 int pld_is_pci_ep_awake(struct device *dev);
 int pld_get_ce_id(struct device *dev, int irq);
 int pld_get_irq(struct device *dev, int ce_id);
-void pld_lock_pm_sem(struct device *dev);
-void pld_release_pm_sem(struct device *dev);
 void pld_lock_reg_window(struct device *dev, unsigned long *flags);
 void pld_unlock_reg_window(struct device *dev, unsigned long *flags);
 int pld_get_pci_slot(struct device *dev);