tests: Disable failing MI_Example/Timing CPU X86 Boot Tests

As noted in this jira issue:
https://gem5.atlassian.net/browse/GEM5-1216, these tests are failing.
We are going to disable them until we can figure out the root cause of
this problem.

Change-Id: I8511beaac0bae3c6d2a42af59035cc4620cd5bb2
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/58769
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>

tests/gem5/x86-boot-tests/test_linux_boot.py

@@ -261,10 +261,10 @@ run_map = {
             8: False,  # Not Supported
         },
         "timing": {
-            1: True,
-            2: True,
-            4: True,
-            8: True,
+            1: False,  # MI_Example does not successfully boot with the Timing
+            2: False,  # Jira: https://gem5.atlassian.net/browse/GEM5-1216
+            4: False,
+            8: False,
         },
         "o3": {
             1: False,  # Timeout