mmc: do not register boot-partitions

boot-partitions break vold on L

Change-Id: Ia8eefbd845079548efbb3dd7ea0cbcce31d76ad1
ipv4: enforce maximum prefixlen of /30 on radio interfaces

Old RILs like to create PtP-interfaces which are no longer
correctly supported by Android 5.0. Fix this by forcing
the netmask of such interfaces to be 255.255.255.252(/30).

Change-Id: Ia13984aa82fbaf12278b48e8ab3a12a88f5cd623