kconfig: Disable x86 clocksource watchdog

Unstable tsc will trigger clocksource watchdog and disable itself, as a
result other clocksource will be elected as the current clocksource
which will result in performace issue on our servers.

RHEL7 also disabled this feature for some issues, see changelog:
[x86] disable clocksource watchdog (Prarit Bhargava) [914709]
Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

arch/x86/Kconfig

@@ -87,7 +87,6 @@ config X86
 	select BUILDTIME_EXTABLE_SORT
 	select CLKEVT_I8253
 	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
-	select CLOCKSOURCE_WATCHDOG
 	select DCACHE_WORD_ACCESS
 	select DMA_DIRECT_OPS
 	select EDAC_ATOMIC_SCRUB