tests: Remove long/nightly ARM Boot tests

The long/nightly tests are failing due to timeout (e.g.:
https://jenkins.gem5.org/job/nightly/398/). We must therefore be more
careful about what we test on a nightly basis.

Each of these ARM boot tests takes an hour and, generally, are largely
the same (just with different CPU cores, cache hierarchy, and memory
system). Given this is largely redundant, some of these tests have been
removed to save on testing time.

Change-Id: I8d80d3e0869aca67aa7279a164bdce85d20f3682
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/65191
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/tests/gem5/arm-boot-tests/test_linux_boot.py b/tests/gem5/arm-boot-tests/test_linux_boot.py
index 9a6f671..6115bb2 100644
--- a/tests/gem5/arm-boot-tests/test_linux_boot.py
+++ b/tests/gem5/arm-boot-tests/test_linux_boot.py
@@ -185,32 +185,8 @@
 
 test_boot(
     cpu="atomic",
-    num_cpus=1,
-    mem_system="classic",
-    memory_class="SingleChannelDDR3_1600",
-    length=constants.long_tag,
-)
-
-test_boot(
-    cpu="timing",
-    num_cpus=1,
-    mem_system="classic",
-    memory_class="SingleChannelDDR3_2133",
-    length=constants.long_tag,
-)
-
-test_boot(
-    cpu="o3",
-    num_cpus=1,
-    mem_system="classic",
-    memory_class="DualChannelDDR3_1600",
-    length=constants.long_tag,
-)
-
-test_boot(
-    cpu="timing",
     num_cpus=4,
-    mem_system="classic",
+    mem_system="no_cache",
     memory_class="HBM2Stack",
     length=constants.long_tag,
 )
@@ -218,39 +194,7 @@
 test_boot(
     cpu="timing",
     num_cpus=2,
-    mem_system="classic",
-    memory_class="DualChannelDDR4_2400",
-    length=constants.long_tag,
-)
-
-test_boot(
-    cpu="timing",
-    num_cpus=2,
-    mem_system="no_cache",
-    memory_class="DualChannelDDR4_2400",
-    length=constants.long_tag,
-)
-
-test_boot(
-    cpu="timing",
-    num_cpus=2,
     mem_system="chi",
     memory_class="DualChannelDDR4_2400",
     length=constants.long_tag,
 )
-
-test_boot(
-    cpu="timing",
-    num_cpus=2,
-    mem_system="mesi_two_level",
-    memory_class="DualChannelDDR4_2400",
-    length=constants.long_tag,
-)
-
-test_boot(
-    cpu="timing",
-    num_cpus=2,
-    mem_system="mi_example",
-    memory_class="DualChannelDDR4_2400",
-    length=constants.long_tag,
-)