MIPS[64]: Skip built-ins/RegExp/property-escapes/generated/* due to timeout

These CL skips the tests the same way it is done on ARM.

Bug: 
Cq-Include-Trybots: master.tryserver.v8:v8_linux_noi18n_rel_ng
Change-Id: I03b5b6cb2c69a4838c649ce7beee6283f3324e6d
Reviewed-on: https://chromium-review.googlesource.com/532876Reviewed-by: Daniel Ehrenberg <littledan@chromium.org>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Cr-Commit-Position: refs/heads/master@{#45900}

test/test262/test262.status

@@ -621,7 +621,7 @@
   '*': [SKIP],
 }],  # variant == wasm_traps
 
-['variant != default or arch == arm or arch == arm64', {
+['variant != default or arch == arm or arch == arm64 or arch == mipsel or arch == mips or arch == mips64 or arch == mips64el', {
   # These tests take a long time to run
   'built-ins/RegExp/property-escapes/generated/*': [SKIP],
 }],  # variant != default or arch == arm or arch == arm64