Remove default value for CONFIG_QUANTUM_OVS_BRIDGE_MAPPINGS
Remove default value for CONFIG_QUANTUM_OVS_BRIDGE_MAPPINGS

The CONFIG_QUANTUM_OVS_BRIDGE_MAPPINGS had a default value of
physnet1:1000:2000, which is a vlan range, not a valid bridge mapping.

Change-Id: Id2d3a5c99a8bea2c41fa2517b7aaaaa35465794b

xbezdick/packstack,pkilambi/packstack,paramite/packstack,pkilambi/packstack,alincalinciuc/packstack,stackforge/packstack,larsks/packstack,harveyzh/packstack,fr34k8/packstack,mahak/packstack,imcsk8/packstack,openstack/packstack,alincalinciuc/packstack,imcsk8/packstack,palmer159/openstack-test,bcrochet/packstack,fr34k8/packstack,weshayutin/packstack,paramite/packstack,bcrochet/packstack,spkane/packstack,harveyzh/packstack,spkane/packstack,paramite/packstack,spkane/packstack,xbezdick/packstack,weshayutin/packstack,stackforge/packstack,harveyzh/packstack,larsks/packstack,mahak/packstack,palmer159/openstack-test,stackforge/packstack,larsks/packstack,pkilambi/packstack,xbezdick/packstack,weshayutin/packstack,alincalinciuc/packstack,radez/packstack,palmer159/openstack-test,imcsk8/packstack,bcrochet/packstack,openstack/packstack,fr34k8/packstack,openstack/packstack,mahak/packstack,radez/packstack,radez/packstack