compat: fix glibc >= 2.14 requirement

compat: fix glibc >= 2.14 requirement

This project uses the vanilla kernels from the Ubuntu
vanilla kernel PPA. As of >= v3.4 vanilla kernel releases,
there are a few files which are binary in the kernel
headers which are linked with dynamic libraries. Of interest
to us here are the ones required to build external modules.

An example:

/lib/modules/3.4.4-030404-generic/build/scripts/genksyms/genksyms

The folks building these packages are using a glibc >= 2.14 and
although the *only* symbol I see being required from glibc >= 2.14
being memcpy():

mcgrof@garbanzo ~/compat (git::master)$ objdump -T
/home/mcgrof/compat-ksrc/lib/modules/3.4.4-030404-generic/build/scripts/genksyms/genksyms

/home/mcgrof/compat-ksrc/lib/modules/3.4.4-030404-generic/build/scripts/genksyms/genksyms:
    file format elf64-x86-64

DYNAMIC SYMBOL TABLE:
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.3.4 __snprintf_chk
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 free
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.3.4 __vfprintf_chk
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 __errno_location
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 ferror
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 isatty
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 fread
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 fclose
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 strlen
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.4   __stack_chk_fail
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 getopt_long
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 strchr
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 _IO_putc
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 fputs
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 fgetc
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 fputc
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 __strdup
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 __libc_start_main
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 strcmp
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 feof
0000000000000000  w   D  *UND*  0000000000000000              __gmon_start__
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 strtol
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 clearerr

Bleh:

0000000000000000      DF *UND*  0000000000000000  GLIBC_2.14  memcpy

0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 fileno
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 malloc
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 _IO_getc
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 ungetc
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 realloc
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.3.4 __printf_chk
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 fopen
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 perror
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 exit
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 fwrite
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.3.4 __fprintf_chk
000000000060b160 g    DO .bss   0000000000000008  GLIBC_2.2.5 stdout
000000000060b168 g    DO .bss   0000000000000008  GLIBC_2.2.5 stdin
000000000060b178 g    DO .bss   0000000000000008  GLIBC_2.2.5 stderr
000000000060b170 g    DO .bss   0000000000000008  GLIBC_2.2.5 optarg

As proposed by Ozan we fix this by re-building some of the required
binaries under scripts/ to build external modules.

For details see:

https://lkml.org/lkml/2012/8/7/489

Signed-off-by: Luis R. Rodriguez <mcgrof@frijolero.org>