intel/compiler: don't compact 3-src instructions with Src1Type or Src2Type bits

intel/compiler: don't compact 3-src instructions with Src1Type or Src2Type bits

We are now using these bits, so don't assert that they are not set. In gen8,
if these bits are set compaction is not possible. On gen9 and CHV platforms
set_3src_control_index() checks these bits (and others) against a table to
validate if the particular bit combination is eligible for compaction or not.

v2
 - Add more detail in the commit message explaining the situation for SKL+
   and CHV (Jason)

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>