libc/newlib: update fetch location

The menu system provides an option to allow a user to request newlib
version 2.0.0. newlib-2.0.0, however, is not available at the download
location currently being used. It is, however, available (as are other
supported versions of newlib) at an alternate location.

Signed-off-by: Trevor Woerner <twoerner@gmail.com>
Message-Id: <75ab5151c7f5dc9086e3.1362334313@suse64>
Patchwork-Id: 224561

 # Bare metal config options

 ## select BARE_METAL

 ##

 ## help 'Bare metal' refers to those programs that run without any kernel.

 ## help

 ## help You probably want to say 'y' here if you plan to use your compiler

 ## help to build bootloaders. It is not yet suitable to build Linux kernels,

 ## help though, because the APCI stuff relies on the target C library headers

 ## help being available?!?!...