cc/gcc: remove --enable-symver option

That option is coming from the original crosstool, and is not entirely
understand here.

Moreover, it breaks with newer gcc-s: 4.6.1 now breaks while configuring
libjava (and probably some other libs as well, untested).

There is an related bug report to the gcc BZ:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49555

If need be, the old behavior can be restored with:
CC_CORE_EXTRA_CONFIG_ARRAY="--enable-symver=gnu"
CC_EXTRA_CONFIG_ARRAY="--enable-symver=gnu"

Reported-by: Bryan Hundven <bryanhundven@gmail.com>
Reviewed-by: Bryan Hundven <bryanhundven@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

# newlib second-part options

config LIBC_NEWLIB_IO_C99FMT

    bool

    prompt "Enable IOs on C99 formats"

    help

      Enable support for IOs on C99 formats.

config LIBC_NEWLIB_IO_LL

    bool

    prompt "Enable IOs on long long"

    help

      Enable support for IOs on long long integers.

config LIBC_NEWLIB_IO_FLOAT

    bool

    prompt "Enable IOs on floats and doubles"

    help

      Enable support for IOs on floating point

      values (float and double).

config LIBC_NEWLIB_IO_LDBL

    bool

    prompt "Enable IOs on long doubles"

    depends on LIBC_NEWLIB_IO_FLOAT

    help

      Enable support for IOs on long doubles.