libc/eglibc: normalize eglibc hidden version names

In the previous patches to glibc and uclibc, we standardized on hidden
version names:

LIBC_<LIBC NAME>_V_<VERSION>

This patch updates EGLIBC to be the same for consistency to:

LIBC_EGLIBC_V_<VERSION>

Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>

 This is NOT the official version of dialog.  This version has been

 significantly modified from the original.  It is for use by the Linux

 kernel configuration script.  Please do not bother Savio Lam with 

 questions about this program.