qcacld-3.0: Rename wlan host driver name for helium target

Rename WLAN host driver name to qca_cld3_adrastea for helium
target.
In addition to satisfy this required symbolic link is created
statically and add adrastea defconfig file.

Change-Id: Id77a1ae01181238965fa666d017e94d827c4c67b
CRs-Fixed: 3126913

.adrastea

@@ -0,0 +1 @@
+.

configs/adrastea_defconfig

@@ -0,0 +1 @@
+include $(WLAN_ROOT)/configs/default_defconfig