hwc: 8x26: Composition policy when WFD connected

When WFD is connected to 8x26
1) On Video transition, have 1 padding round if external connected.
Required to shift pipes across mixers.
2) Request DMA pipe always for FB on WFD.
Necessary for rotation + writeback
3) Disable non-worm-hole calcs on external (because of 2)
4) Disable action-safe calcs on external (because of 2)

Change-Id: I63b50b2477db443f9ea1d3fa610b59295c9359b7
5 files changed