[U-Boot] V3 Zoom hw reset

The i2c patch is a cleaned up version of the one I RFC-ed to the list earlier. It addresses Nishanth's concerns by using the kernel's algorithm and by making the major parameters overridable by a board config. Jean's request for no weak function is addressed by this being done only with #defines. I have reverified on the hw listed in the commit.

The twl4030 patch I don't think anyone had a problem with.

The twl4030 hw reset has been generalized. After analyzing beagle schematics, I believe this can be used by anyone with supporting hw. So the function stays in power.c and the #ifdef's are removed.