Make linux's chromeos_with_codecs* compile w/o VAAPI hw acceleration

This CL makes chromeos_with_codecs* compile without VA-API hardware
acceleration (used for video and image dec/encoding), which is a
legitimate target (at least to compile) that in the past has been
inadvertently broken.

Note that the cros_chrome_sdk* bots (e.g. chromeos-amd64-generic-rel,
based on simplechrome checkouts) still compile with the official
respective chromeos args.gn, that includes use_vaapi (or
use_v4l2_codec).

Bug: 1006266
Change-Id: I322fe10cac403fbee0e2ef17732fe38e88c2b564
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1815846Reviewed-by: Ben Pastene <bpastene@chromium.org>
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699503}

tools/mb/mb_config.pyl

@@ -1278,23 +1278,23 @@
     ],
 
     'chromeos_with_codecs_debug_bot': [
-      'chromeos_with_codecs', 'debug_bot', 'use_vaapi',
+      'chromeos_with_codecs', 'debug_bot',
     ],
 
     'chromeos_with_codecs_release_bot': [
-      'chromeos_with_codecs', 'release_bot', 'use_vaapi',
+      'chromeos_with_codecs', 'release_bot',
     ],
 
     'chromeos_with_codecs_release_bot_coverage': [
-      'chromeos_with_codecs', 'release_bot', 'use_vaapi', 'use_clang_coverage',
+      'chromeos_with_codecs', 'release_bot', 'use_clang_coverage',
     ],
 
     'chromeos_with_codecs_release_trybot': [
-      'chromeos_with_codecs', 'release_trybot', 'use_vaapi', 'no_symbols',
+      'chromeos_with_codecs', 'release_trybot', 'no_symbols',
     ],
 
     'chromeos_with_codecs_release_trybot_code_coverage': [
-      'chromeos_with_codecs', 'release_trybot', 'use_vaapi', 'no_symbols',
+      'chromeos_with_codecs', 'release_trybot', 'no_symbols',
       'use_clang_coverage', 'partial_code_coverage_instrumentation',
     ],
 
@@ -2467,10 +2467,6 @@
       'gn_args': 'use_dummy_lastchange=true',
     },
 
-    'use_vaapi': {
-      'gn_args': 'use_vaapi=true',
-    },
-
     'v8_simulate_arm': {
       'gn_args': 'target_cpu="x86" v8_target_cpu="arm"',
     },