Fix CPU dimension for FYI bots for PartitionAlloc-Everywhere

Continuation of crrev.com/c/2517220

For Android, machines don't have CPU dimensions, so specifying arm64
results in matching nothing.
For Windows, machines only have x86-64 dimension. Use those machines
even for x86 case, because the binary built for x86 can be run on x64.

Bug: 1121427
Change-Id: I0c3d86804903fba2ebca02e22eecba536d48eca3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2532018Reviewed-by: Garrett Beaty <gbeaty@chromium.org>
Commit-Queue: Garrett Beaty <gbeaty@chromium.org>
Commit-Queue: Bartek Nowierski <bartekn@chromium.org>
Auto-Submit: Bartek Nowierski <bartekn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826498}

testing/buildbot/chromium.fyi.json

@@ -9936,7 +9936,6 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "cpu": "arm64",
               "device_type": "walleye",
               "os": "Android"
             }
@@ -9959,7 +9958,6 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "cpu": "arm64",
               "device_type": "walleye",
               "os": "Android"
             }
@@ -61005,7 +61003,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "cpu": "x86-32",
+              "cpu": "x86-64",
               "os": "Windows-10-18363"
             }
           ],
@@ -61027,7 +61025,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "cpu": "x86-32",
+              "cpu": "x86-64",
               "os": "Windows-10-18363"
             }
           ],

testing/buildbot/waterfalls.pyl

@@ -2168,7 +2168,6 @@
         },
         'mixins': [
           'walleye',
-          'arm64',
         ],
       },
       'android-paeverywhere-arm64-fyi-rel': {
@@ -2177,7 +2176,6 @@
         },
         'mixins': [
           'walleye',
-          'arm64',
         ],
       },
       'chromeos-amd64-generic-lacros-rel': {
@@ -2777,7 +2775,7 @@
         },
         'mixins': [
           'win10',
-          'x86-32',
+          'x86-64',
         ],
       },
       'win-paeverywhere-x86-fyi-rel': {
@@ -2786,7 +2784,7 @@
         },
         'mixins': [
           'win10',
-          'x86-32',
+          'x86-64',
         ],
       },
       'win-pixel-tester-rel': {