utils/getconf.c fails to build with old host libc

[Bernhard Reutner-Fischer]

On Sat, Dec 04, 2010 at 10:29:42AM +0100, Thomas Petazzoni wrote:

>On older glibc (like 2.7), the _SC_V7_* symbols are not defined,
>making the build of current uClibc fail on Debian Lenny systems and
>other systems using a fairly old glibc. So we make sure to only use
>the specs names that are defined by the host C library.

applied, thanks!