i8253: Convert i8253_lock to raw_spinlock

i8253_lock needs to be a real spinlock in preempt-rt, i.e. it can
not be converted to a sleeping lock.

Convert it to raw_spinlock and fix up all users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
LKML-Reference: <20100217163751.030764372@linutronix.de>