Fix wrong lib directory for x64 and mips64el target.

Fix wrong lib directory for x64 and mips64el target.

Linker report incompatible target errors on crtbegin_so.o and
crtend_so.o because /usr/lib is set incorrectly on x64 target.

mips64el is also changed and arm64 keep use /usr/lib after checking
each platform ndk toolchains but not verified because no environment.

BUG=none

Committed: https://crrev.com/964602788cc2d0a2b0cb89fcbe1691852d25f251
Cr-Commit-Position: refs/heads/master@{#316128}

[haltonhuo, 2015-02-11 06:08:01]

halton.huo@intel.com changed reviewers:
+ brettw@chromium.org

[haltonhuo, 2015-02-11 06:08:02]

PTAL

[brettw, 2015-02-12 18:45:08]

lgtm

[haltonhuo, 2015-02-13 01:33:15]

The CQ bit was checked by halton.huo@intel.com

[commit-bot: I haz the power, 2015-02-13 01:33:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/912273002/1

[commit-bot: I haz the power, 2015-02-13 02:01:31]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-13 02:02:50]

Patchset 1 (id:??) landed as
https://crrev.com/964602788cc2d0a2b0cb89fcbe1691852d25f251
Cr-Commit-Position: refs/heads/master@{#316128}