nine: Drop use of TGSI_OPCODE_CND.

nine: Drop use of TGSI_OPCODE_CND.

This was the only state tracker emitting it, and hardware was just having
to lower it anyway (or failing to lower it at all).

v2: Extracted from a larger patch by Jose (which also dropped DP2A), fixed
    to actually not reference TGSI_OPCODE_CND.  Change by anholt.

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
Reviewed-by: Axel Davy <axel.davy@ens.fr>
Reviewed-by: David Heidelberg <david@ixit.cz>