x86/build/x86_64_defconfig: Enable CONFIG_R8169

Very common PCIe ethernet card. Already enabled in i386_defconfig.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Link: http://lkml.kernel.org/r/20170306085748.85957-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>