qcacld-3.0: Print build timestamp with driver version

As part of driver init, the version string gets printed. To help in
debugging, also print a timestamp from when the driver was compiled.

Change-Id: Icf064af6a0d84434d239b54603092bf2276df596
CRs-Fixed: 2059303
diff --git a/Kbuild b/Kbuild
index c60815d..169b024 100644
--- a/Kbuild
+++ b/Kbuild
@@ -2158,3 +2158,6 @@
 # Module information used by KBuild framework
 obj-$(CONFIG_QCA_CLD_WLAN) += $(MODNAME).o
 $(MODNAME)-y := $(OBJS)
+
+# inject some build related information
+CDEFINES += -DBUILD_TIMESTAMP=\"$(shell date -u +'%Y-%m-%dT%H:%M:%SZ')\"