[badge]: add vs build badge (sonic-net#898)

remove build badge for cavium and p4

Author: lguohan

README.md

@@ -1,7 +1,6 @@
 Broadcom[![Broadcom](https://sonic-jenkins.westus2.cloudapp.azure.com/job/broadcom/job/sonic-swss-build/badge/icon)](https://sonic-jenkins.westus2.cloudapp.azure.com/job/broadcom/job/sonic-swss-build/)
-Cavium[![Cavium](https://sonic-jenkins.westus2.cloudapp.azure.com/job/cavium/job/sonic-swss-build/badge/icon)](https://sonic-jenkins.westus2.cloudapp.azure.com/job/cavium/job/sonic-swss-build/)
 Mellanox[![Mellanox](https://sonic-jenkins.westus2.cloudapp.azure.com/job/mellanox/job/sonic-swss-build/badge/icon)](https://sonic-jenkins.westus2.cloudapp.azure.com/job/mellanox/job/sonic-swss-build/)
-P4[![P4](https://sonic-jenkins.westus2.cloudapp.azure.com/job/p4/job/sonic-swss-build/badge/icon)](https://sonic-jenkins.westus2.cloudapp.azure.com/job/p4/job/sonic-swss-build/)
+VS[![VS](https://sonic-jenkins.westus2.cloudapp.azure.com/job/vs/job/sonic-swss-build/badge/icon)](https://sonic-jenkins.westus2.cloudapp.azure.com/job/vs/job/sonic-swss-build/)
 
 # SONiC - SWitch State Service - SWSS