Can't find the option, and my belief is that Microsoft have chosen to remove it.
Quick workaround if required (although I'm sure there are other ways to accomplish this):
[VBA]
Dim cht As ChartObject
For Each cht In shGraphs.ChartObjects
cht.Chart.Legend.Font.Size = 14
cht.Chart.Legend.Position = xlLegendPositionRight
Next cht
[/VBA]
I've attached this to a worksheet event that causes a recalculation.