Optional regulators in bulk operations - reverted patch

[Heiner Kallweit]

Hi Bjorn,

I just came across a use case where I wanted to deal with optional
regulators in bulk operations. I was about to submit a related
patch when I saw that you submitted basically the same in
3ff3f518a135 "regulator: Make bulk API support optional supplies"
and reverted it later stating that you misunderstood the API.

How does this extension break the API? To me it sounds like a
neat feature.

The only thing I can think of if that we have to assume that
struct regulator_bulk_data is zero-initialized to ensure
backwards-compatibility (use "normal" get as default).

Rgds, Heiner