[PATCH] backlight: pwm_bl: Do not make the regulator mandatory

[Shawn Guo]

On Mon, Nov 25, 2013 at 11:26:53AM -0200, Fabio Estevam wrote:
> Looks like we need to apply this one to make sure backlight works:
> http://permalink.gmane.org/gmane.linux.ports.arm.kernel/281826

But per Thierry's comment below, this is the exactly the case that we
should avoid - patch individual board DTS file to add a dummy/fake
regulator to get it through.

| But even so, the regulator core now has functionality to return a dummy
| regulator if none is specified in DT, specifically so that users don't
| have to special case the handling of "optional" regulators. That should
| be enough to keep all boards working even if no power-supply property
| was given in the DTS. As a matter of fact it's a constellation that I
| explicitly tested and found to work well.

Shawn