Unify coding order of MC filters between blocks and frame header.

In VP9, the order for frame header was: [0] smooth, [1] regular, [2]
sharp, [3] bilinear. Per-block, the order was [0] regular, [1] smooth
and [2] sharp. For VP10, swap smooth/regular in the frame header so
that the block ordering and frame header ordering are interchangeable.

See issue #1046.

Change-Id: Ic9ec5964874375e40cd59bef50b489a76cbe4365