[YOCTO #815] Added --sysroot into COLLECT_GCC_OPTIONS to allow the
collect2 support user specifed sysroot.
(From OE-Core rev: 868f8d3dd04e3c6dbbce154742cf877fda460a3e)
Signed-off-by: Lianhao Lu <lianhao.lu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>