currently, we have 3 docker files(cephcsi,rbd,cephfs) in the ceph-csi repo.
[commit ](85e121ebfe)
added by John to build a single image which can act as rbd or
cephfs based on the input configuration.
This PR updates the makefile and kubernetes templates to use
the unified image and also its deletes the other two dockerfiles.
Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>