gcc: promote PKGVERSION and BUGURL options to toolchain level

This patch promotes the PKGVERSION and BUGURL options to toolchain level so that
all toolchain components supporting them can benefit from them.

These options are passed to configure through --with-pkgversion and
--with-bugurl.

They are supported by binutils 2.18+, gcc 4.3+, eglibc 2.9+ and gdb 7.0+.

Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>

 # x86 specific options

 ## select ARCH_SUPPORTS_32

 ## select ARCH_SUPPORTS_64

 ## select ARCH_DEFAULT_32

 ## select ARCH_USE_MMU

 ## select ARCH_SUPPORT_ARCH

 ## select ARCH_SUPPORT_CPU

 ## select ARCH_SUPPORT_TUNE

 ##

 ## help The x86 architecture, as defined by:

 ## help     32-bit (ia32) : http://www.intel.com/

 ## help     64-bit (amd64): http://www.amd.com/us-en/Processors/DevelopWithAMD/0,,30_2252_875_7044,00.html