qcacld-3.0: hdd: Refactor the Green AP feature

Refactor the hdd portion of the Green AP feature so that it can be
easily excluded when the feature is not enabled.

Change-Id: I986c5ab7640b3182a12bef93748affefba067251
CRs-Fixed: 2216247
diff --git a/Kbuild b/Kbuild
index ff79014..7dbf613 100644
--- a/Kbuild
+++ b/Kbuild
@@ -500,6 +500,10 @@
 HDD_OBJS+=	$(HDD_SRC_DIR)/wlan_hdd_fips.o
 endif
 
+ifeq ($(CONFIG_QCACLD_FEATURE_GREEN_AP),y)
+HDD_OBJS+=	$(HDD_SRC_DIR)/wlan_hdd_green_ap.o
+endif
+
 ifeq ($(CONFIG_WLAN_FEATURE_LPSS),y)
 HDD_OBJS +=	$(HDD_SRC_DIR)/wlan_hdd_lpass.o
 endif