Clean up architectures in xcconfig files

Clean up architectures in xcconfig files
<http://webkit.org/b/126794>

Reviewed by Andy Estes.

Source/JavaScriptCore:

* Configurations/Base.xcconfig:
* Configurations/JavaScriptCore.xcconfig: Remove armv6, ppc.
* Configurations/ToolExecutable.xcconfig: Sort.
- Add new arch.

Source/WebCore:

* Configurations/Base.xcconfig:
* Configurations/WebCore.xcconfig: Remove armv6.
* DerivedSources.make: Remove armv6, armv7f. Sort.
- Add new arch.

Source/WebKit/mac:

* Configurations/WebKit.xcconfig: Remove armv6, armv7f, ppc.
- Add new arch.

Source/WTF:

* Configurations/Base.xcconfig:
- Add new arch.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@161713 268f45cc-cd09-0410-ab3c-d52691b4dbfc