x86/PCI: Convert pci_config_lock to raw_spinlock

pci_config_lock must be a real spinlock in preempt-rt. Convert it to
raw_spinlock. No change for !RT kernels.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>