In the hypershade editor, click on the input button where you linked the file. (ie. at the end of the color slider, if you maped to the color channel) towards the bottom of this window you will see 'UV Coordinates', maximize it and open its input channel. 3 lines down, you will see 'Rotate Frame', set that to 180.
And after calming me down with some orange slices and some fetal spooning,
E.T. revealed to me his singular purpose.
--TOOL, 10,000 Days---