Use PIPE_SWIZZLE_* everywhere.
Use X/Y/Z/W/0/1 instead of RED, GREEN, BLUE, ALPHA, ZERO, ONE.
The new enum is called pipe_swizzle.
Acked-by: Jose Fonseca <jfonseca@vmware.com>
Now that tiling is in place, we can expose the other formats. Depth is
still broken (need to make changes in the shader), but if you don't expose
it things crash all over. SNORM is dropped, but we could re-add it later
with some shader fixes to handle converting between [0,1] and [-1,1].
