i965: Reorder sources of the untyped atomic opcode.

i965: Reorder sources of the untyped atomic opcode.

This is consistent with the untyped surface read opcode.  From now on
all typed and untyped surface access opcodes will follow the same
pattern: src[0] will be the message payload, src[1] will be the
surface index and src[2] will be a control immediate (atomic operation
for atomic opcodes and number of vector components for surface read
and write opcodes).

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>