qcacld-3.0: Add SERIALIZE_VDEV_RESP_TIMER in Kbuild

SERIALIZE_VDEV_RESP_TIMER macro enables target_if common code for
vdev response timer callback handlers.

Change-Id: Ic1f647a99a0c90f2492bdb0c9d2d525fabb6d86a
CRs-Fixed: 2507526

Kbuild

@@ -2839,6 +2839,7 @@ cppflags-y += -DFEATURE_NBUFF_REPLENISH_TIMER
 cppflags-y += -DPEER_CACHE_RX_PKTS
 cppflags-y += -DPCIE_REG_WINDOW_LOCAL_NO_CACHE
 
+cppflags-y += -DSERIALIZE_VDEV_RESP_TIMER
 cppflags-y += -DTGT_IF_VDEV_MGR_CONV
 
 ccflags-$(CONFIG_HASTINGS_BT_WAR) += -DHASTINGS_BT_WAR