x86/defconfig: Remove stale, old Kconfig options

Remove old, dead Kconfig options (in order appearing in this commit):

 - EXPERIMENTAL is gone since v3.9;
 - IP_NF_TARGET_ULOG: commit d4da843e ("netfilter: kill remnants of ulog targets");
 - USB_LIBUSUAL: commit f61870ee

 ("usb: remove libusual");

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1500526885-4341-1-git-send-email-krzk@kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>