[openssl/openssl] 21c9a4: Fix Configure test for -mips in CFLAGS

[Mike Gilbert]

  Branch: refs/heads/openssl-3.0
  Home:   https://github.com/openssl/openssl
  Commit: 21c9a485e7b55fef3bf0f008cb97f4dfbade9a4b
      https://github.com/openssl/openssl/commit/21c9a485e7b55fef3bf0f008cb97f4dfbade9a4b
  Author: Mike Gilbert <floppym at gentoo.org>
  Date:   2023-03-20 (Mon, 20 Mar 2023)

  Changed paths:
    M Configure

  Log Message:
  -----------
  Fix Configure test for -mips in CFLAGS

We want to add -mips2 or -mips3 only if the user hasn't already
specified a mips version in CFLAGS. The existing test was a
double-negative.

CLA: trivial

Fixes: https://github.com/openssl/openssl/issues/20214

Reviewed-by: Tomas Mraz <tomas at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20273)

(cherry picked from commit 8b399c5e51b4d010650cb344a67a696daf096a05)