GitLab

Fixing two errors:
 - ERROR Unresolved dependencies.
   //:gn_only(//build/toolchain/linux:mipsel)
   needs //third_party/libjpeg_turbo:simd_asm(//build/toolchain/linux:mipsel)
 by including //third_party/libjpeg_turbo:simd_asm target
 only for x86 and x64, where it exists
 - incompatible pointer types in usrsctp
 by ignoring warnings for this module

TEST=gn gen out/mips-linux --args="is_debug=false target_os=\"linux\" target_cpu=\"mipsel\" is_clang=false"
     ninja -C out/mips-linux/ chrome

Review URL: https://codereview.chromium.org/1094793004

Cr-Commit-Position: refs/heads/master@{#327245}