arch/sparc: Remove the check #ifndef __LINUX_SPINLOCK_TYPES_H

Saw these compile errors on SPARC when queued rwlock feature is enabled.

   CC      kernel/locking/qrwlock.o
In file included from ./include/asm-generic/qrwlock_types.h:5,
                  from ./arch/sparc/include/asm/qrwlock.h:4,
                  from kernel/locking/qrwlock.c:24:
./arch/sparc/include/asm/spinlock_types.h:5:3: error:
         #error "please don't include this file directly"

SPARC has this guard which causes compile error when spinlock_types.h
is included directly.
@ifndef __LINUX_SPINLOCK_TYPES_H
@ error "please don't include this file directly"
@endif

Remove this un-necessary "ifndef __LINUX_SPINLOCK_TYPES_H" stanza from SPARC.

Signed-off-by: Babu Moger <babu.moger@oracle.com>
Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>