[qca-nss-clients] Use only major and minor version in Makefile

 Makefiles use only major and minor version. Get rid of
 revision and stable version from KERNELVERSION variable

Signed-off-by: Ratheesh Kannoth <rkannoth@codeaurora.org>
Change-Id: If39ed1b071d1d9334116b4ef865e986267e46934
diff --git a/Makefile b/Makefile
index 2942030..c520187 100644
--- a/Makefile
+++ b/Makefile
@@ -10,6 +10,8 @@
 ccflags-y += -DNSS_TUN6RD_DEBUG_LEVEL=0
 ccflags-y += -Werror
 
+KERNELVERSION := $(word 1, $(subst ., ,$(KERNELVERSION))).$(word 2, $(subst ., ,$(KERNELVERSION)))
+
 obj-$(bridge-mgr)+= bridge/
 obj-$(capwapmgr)+= capwapmgr/
 obj-$(dtlsmgr)+= dtls/$(DTLSMGR_DIR)/