qcacld-3.0: Featurize fastpath feature

Featurize fastpath feature cleanly and
also disable unused code when Fastpath
is enabled.

Change-Id: I3922af873ef32544fdca37be0b110ebbc2abc45a
CRs-Fixed: 2226918
diff --git a/Kbuild b/Kbuild
index 41216e0..49943f8 100644
--- a/Kbuild
+++ b/Kbuild
@@ -883,6 +883,12 @@
 TXRX_OBJS +=     $(TXRX_DIR)/ol_txrx_ipa.o
 endif
 
+ifeq ($(CONFIG_WLAN_FASTPATH), y)
+TXRX_OBJS +=     $(TXRX_DIR)/ol_tx_ll_fastpath.o
+else
+TXRX_OBJS +=     $(TXRX_DIR)/ol_tx_ll_legacy.o
+endif
+
 ifeq ($(CONFIG_LITHIUM), y)
 ############ DP 3.0 ############
 DP_INC := -I$(WLAN_COMMON_ROOT)/dp/inc \