Update doc name and path for dell emc vnx and unity driver

Change-Id: If85f12f90e2494fe0d92c0df3862b5327321c18e
Closes-bug: #1754550

doc/source/configuration/shared-file-systems/drivers.rst

@@ -11,6 +11,8 @@ Share drivers
    drivers/generic-driver.rst
    drivers/cephfs-native-driver.rst
    drivers/dell-emc-vmax-driver.rst
+   drivers/dell-emc-unity-driver.rst
+   drivers/dell-emc-vnx-driver.rst
    drivers/glusterfs-driver.rst
    drivers/glusterfs-native-driver.rst
    drivers/hdfs-native-driver.rst
@@ -18,8 +20,6 @@ Share drivers
    drivers/zfs-on-linux-driver.rst
    drivers/zfssa-manila-driver.rst
    drivers/emc-isilon-driver.rst
-   drivers/emc-vnx-driver.rst
-   drivers/emc-unity-driver.rst
    drivers/hitachi-hnas-driver.rst
    drivers/hitachi-hsp-driver.rst
    drivers/hpe-3par-share-driver.rst