qcacmn: Ensure shadow_v2 config is initialized

Fix a crash durring hif_wlan_enable where the shadow_v2 was
dereferenced while pointing to garbage memory.

For legacy ce, uninitialized values from the stack were left
in the pld shadow_v2 config.  The checks to skip printing the
shadow_v2 config were confused by uninitized stack memory and
the driver tries to dereference unitialized shadow_v2 memory.

Ensure the configuration is filled with NULL & 0 when it is
not applicable.

Change-Id: I668fcf78b1a7c8e6e235d96e428a9808a4e072c7
CRs-Fixed: 2001315

hif/src/ce/ce_service.c

@@ -2564,7 +2564,10 @@ static void ce_ring_setup_legacy(struct hif_softc *scn, uint8_t ring_type,
 static void ce_prepare_shadow_register_v2_cfg_legacy(struct hif_softc *scn,
 			    struct pld_shadow_reg_v2_cfg **shadow_config,
 			    int *num_shadow_registers_configured)
-{ /* noop */ }
+{
+	*num_shadow_registers_configured = 0;
+	*shadow_config = NULL;
+}
 
 struct ce_ops ce_service_legacy = {
 	.ce_get_desc_size = ce_get_desc_size_legacy,