locking/rtmutex: Prevent future include recursion hell

rtmutex only needs raw_spinlock_t, but it includes spinlock_types.h, which
is not a problem on an non RT enabled kernel.

RT kernels substitute regular spinlocks with 'sleeping' spinlocks, which
are based on rtmutexes, and therefore must be able to include rtmutex.h.

Include <linux/spinlock_types_raw.h> instead.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.428224188@linutronix.de