locking: Move MCS struct definition to public header

Move the definition of the struct mcs_spinlock from the private
mcs_spinlock.h header in kernel/locking to the mcs_spinlock.h
asm-generic header, since we will need to reference it from the
qspinlock.h header in subsequent commits.

Reviewed-by: Barret Rhoden <[e-mail]>
Signed-off-by: Kumar Kartikeya Dwivedi <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexei Starovoitov <[e-mail]>

include/asm-generic/mcs_spinlock.h

···
 #ifndef __ASM_MCS_SPINLOCK_H
 #define __ASM_MCS_SPINLOCK_H
 
+struct mcs_spinlock {
+	struct mcs_spinlock *next;
+	int locked; /* 1 if lock acquired */
+	int count;  /* nesting count, see qspinlock.c */
+};
+
 /*
  * Architectures can define their own:
  *

kernel/locking/mcs_spinlock.h

···
 
 #include <asm/mcs_spinlock.h>
 
-struct mcs_spinlock {
-	struct mcs_spinlock *next;
-	int locked; /* 1 if lock acquired */
-	int count;  /* nesting count, see qspinlock.c */
-};
-
 #ifndef arch_mcs_spin_lock_contended
 /*
  * Using smp_cond_load_acquire() provides the acquire semantics