Debian: Add dependency on ${misc:Depends}

Debian: Add dependency on ${misc:Depends}

Add dependency on ${misc:Depends} to openvswitch-brcompat and ovsdbmonitor.
As reported by Lintian:

	The source package uses debhelper, but it does not include
	${misc:Depends} in the given binary package's debian/control entry.
	Any debhelper command may add dependencies to ${misc:Depends} that
	are required for the work that it does, so recommended best
	practice is always add ${misc:Depends} to the dependencies of each
	binary package if debhelper is in use.

	Refer to the debhelper(7) manual page for details.