Remove unused ovs_dkms_package_name

This was used when Debian required the openvswitch-datapath-dkms
package but the package was removed long time ago.

Installation of that package was disabled by [1]. The logic to install
the package was completely removed by [2] and now it is no longer used.

[1] f4d19a7a07
[2] 3ff72b5736

Change-Id: Id4133d74bfed217ca8a58f136d665d76cc233fb0

manifests/params.pp

@@ -9,7 +9,6 @@ class vswitch::params {
       # OVS2.5 in Red Hat family is unified package which will support plain
       # OVS and also DPDK (if enabled at runtime).
       $ovs_dpdk_package_name = 'openvswitch'
-      $ovs_dkms_package_name = undef
       $ovs_service_name      = 'openvswitch'
       $ovsdb_service_name    = undef
       $ovs_service_hasstatus = undef
@@ -19,7 +18,6 @@ class vswitch::params {
     'Debian': {
       $ovs_package_name      = 'openvswitch-switch'
       $ovs_dpdk_package_name = 'openvswitch-switch-dpdk'
-      $ovs_dkms_package_name = 'openvswitch-datapath-dkms'
       $ovs_service_name      = 'openvswitch-switch'
       $ovsdb_service_name    = undef
       $ovs_service_hasstatus = true