x86/PCI: Select CONFIG_PCI_LOCKLESS_CONFIG

All x86 PCI configuration space accessors have either their own
serialization or can operate completely lockless (ECAM).

Disable the global lock in the generic PCI configuration space accessors.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <helgaas@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/20170316215057.295079391@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0efb4c9..0652c9f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -166,6 +166,7 @@
 	select HAVE_UNSTABLE_SCHED_CLOCK
 	select HAVE_USER_RETURN_NOTIFIER
 	select IRQ_FORCED_THREADING
+	select PCI_LOCKLESS_CONFIG
 	select PERF_EVENTS
 	select RTC_LIB
 	select RTC_MC146818_LIB