wlan: Add support to build wearable targets for msm-4.9 kernel

When upgrading wearable targets to support msm-4.9 kernel, if
WLAN_BLD_DIR is a relative path then build is failing with the error
unable to de-refer header files defined locally.

To avoid this, use absolute path for WLAN_BLD_DIR based on
ANDROID_BUILD_TOP.

Change-Id: Ia3e5691d83dbc6a2bbe84e63cea48e2267b64503
CRs-Fixed: 2225760
diff --git a/Android.mk b/Android.mk
index e43af06..e582b54 100644
--- a/Android.mk
+++ b/Android.mk
@@ -58,9 +58,13 @@
     WLAN_BLD_DIR := vendor/qcom/opensource/wlan
 endif
 else
+ifneq ($(ANDROID_BUILD_TOP),)
+    WLAN_BLD_DIR := $(ANDROID_BUILD_TOP)/device/qcom/msm8909w/opensource/wlan
+else
     WLAN_BLD_DIR := device/qcom/msm8909w/opensource/wlan
 endif
 endif
+endif
 
 # DLKM_DIR was moved for JELLY_BEAN (PLATFORM_SDK 16)
 ifeq (1,$(filter 1,$(shell echo "$$(( $(PLATFORM_SDK_VERSION) >= 16 ))" )))
@@ -124,11 +128,9 @@
 
 # This is set once per LOCAL_PATH, not per (kernel) module
 
-ifneq ($(TARGET_SUPPORTS_WEARABLES),true)
 ifneq ($(ANDROID_BUILD_TOP),)
 KBUILD_OPTIONS := WLAN_ROOT=$(WLAN_BLD_DIR)/prima
 endif
-endif
 
 ifeq ($(KBUILD_OPTIONS),)
 KBUILD_OPTIONS := WLAN_ROOT=$(KERNEL_TO_BUILD_ROOT_OFFSET)$(WLAN_BLD_DIR)/prima