luci-mod-network: let sourcefilter option available for most proto

sourcefilter option should be available for proto like:
'dhcpv6'
'directip'
'ppp'
'pppoe'
'pppoa'
'pptp'
'qmi'
'mbim'
'ncm'
'3g'

Signed-off-by: Chen Minqiang <ptpt52@gmail.com>