add path for TRTRZ and UNMRZ in ILAENV

[langou]

This completes #1289

In #1289, @jschueller introduced dedicated paths for CTZRZF (NB2) and CUNMRZ (NB4) in GELSY

      INFO = 0
      NB1 = ILAENV( 1, 'CGEQRF', ' ', M, N, -1, -1 )
-      NB2 = ILAENV( 1, 'CGERQF', ' ', M, N, -1, -1 )
+      NB2 = ILAENV( 1, 'CTZRZF', ' ', M, N, -1, -1 )
      NB3 = ILAENV( 1, 'CUNMQR', ' ', M, N, NRHS, -1 )
-      NB4 = ILAENV( 1, 'CUNMRQ', ' ', M, N, NRHS, -1 )
+      NB4 = ILAENV( 1, 'CUNMRZ', ' ', M, N, NRHS, -1 )
      NB = MAX( NB1, NB2, NB3, NB4 )
      LWKOPT = MAX( 1, MN+2*N+NB*(N+1), 2*MN+NB*NRHS )
      WORK( 1 ) = CMPLX( LWKOPT )

But, as pointed out by @martin-frbg, #1289 (comment), these paths did not exist in ILAENV. So then ILAENV was returning the default value of NB2 = 1 and NB4 = 1.

We might accept the previous code (before PR #1289) as saying "the optimal block size for TZRZF is the same as the block size for GERQF", so we do not need to create a dedicated path for TZRZF in ILAENV, we simply call ILAENV with argument GERQF.

This commits keeps the PR as is and adds the two paths to ILAENV.

Note: It might feel "lazy" to drop the paths at the start like this. But I think it is better than hide the paths in a series of nested IFs. They are cons and pros to the nested IFs. I chose to drop it at the top.