Allow DataView of Reset <=> [UInt<1>, AsyncReset] (#3181)

Change what DataView allows in its type checking to enable Reset to be
viewed as either a UInt<1> or an AsyncReset.  This enables more flexible
DataViews which match already allowable Chisel and FIRRTL connection
semantics.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@sifive.com>