Remove unused/bogus resets

[glennchid]

Several blocks make use of the reset signal which propagates around the design and originates from the PS. This may be asserted at initialisation by the PS, but there does not seem to be any user-driven way to assert this. In many cases, where a reset may be wanted, this is probably being used by mistake instead of a user-driven functional/local reset. In most cases though a reset signal should not be required.