[SPARC]: Add missing rw can_lock macros

Fix a link failure by adding the missing can_lock macros for the rw
locks.

Signed-off-by: Bob Breuer <breuerr@mc.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/asm-sparc/spinlock.h

diff --git a/include/asm-sparc/spinlock.h b/include/asm-sparc/spinlock.h
index 3350c90..1c75474 100644
--- a/include/asm-sparc/spinlock.h
+++ b/include/asm-sparc/spinlock.h
@@ -154,6 +154,9 @@
 #define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
 #define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
 
+#define __raw_read_can_lock(rw) (!((rw)->lock & 0xff))
+#define __raw_write_can_lock(rw) (!(rw)->lock)
+
 #endif /* !(__ASSEMBLY__) */
 
 #endif /* __SPARC_SPINLOCK_H */