atomics/treewide: Make unconditional inc/dec ops optional

Many of the inc/dec ops are mandatory, but for most architectures inc/dec are
simply trivial wrappers around their corresponding add/sub ops.

Let's make all the inc/dec ops optional, so that we can get rid of these
boilerplate wrappers.

The instrumented atomics are updated accordingly.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-17-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/h8300/include/asm/atomic.h

@@ -69,13 +69,6 @@ ATOMIC_OPS(sub, -=)
 #undef ATOMIC_OP_RETURN
 #undef ATOMIC_OP
 
-#define atomic_inc_return(v)		atomic_add_return(1, v)
-#define atomic_dec_return(v)		atomic_sub_return(1, v)
-
-#define atomic_inc(v)			(void)atomic_inc_return(v)
-
-#define atomic_dec(v)			(void)atomic_dec_return(v)
-
 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 {
 	int ret;