[cq] Add mips compile trybots.

testing/commit_queue/config.json

 {
     "commit_burst_delay": 60,
     "commit_user": "commit-bot@chromium.org",
     "cq_status_url": "https://chromium-cq-status.appspot.com",
     "git_repo_url": "https://chromium.googlesource.com/v8/v8",
     "hide_ref_in_committed_msg": true,
     "max_commit_burst": 1,
     "project_bases_legacy_from_git_repo_url": true,
     "remote_branch": "refs/pending/heads/master",
     "rietveld_url": "https://codereview.chromium.org",
@@ skipping 29 matching lines @@
                     ],
                     "v8_linux_chromium_gn_rel": [
                         "defaulttests"
                     ],
                     "v8_linux_dbg": [
                         "defaulttests"
                     ],
                     "v8_linux_gcc_compile_rel": [
                         "defaulttests"
                     ],
+                    "v8_linux_mipsel_compile_rel": [
+                        "defaulttests"
+                    ],
+                    "v8_linux_mips64el_compile_rel": [
+                        "defaulttests"
+                    ],
                     "v8_linux_nodcheck_rel": [
                         "defaulttests"
                     ],
                     "v8_linux_rel": [
                         "defaulttests"
                     ],
                     "v8_mac_rel": [
                         "defaulttests"
                     ],
                     "v8_presubmit": [
@@ skipping 11 matching lines @@
                     "v8_win_rel": [
                         "defaulttests"
                     ]
                 }
             },
             "triggered": {}
         }
     },
     "version": 1
 }