[PATCH v2] MIPS/opcodes: Fix floor/round exclusions for R5900

[Maciej W. Rozycki]

On Sun, 18 Jan 2026, David Guillen Fandos wrote:

> MIPS R5900 does not feature ceil/floor/round instructions, but only
> ceil is correctly excluded at the moment. Correct the other two.
                                           ^
 I have committed your change with two spaces inserted after the full stop 
above, as per the GNU Coding Standards.  Thank you for your contribution.

  Maciej