Enable queued rwlocks for SPARC. Here are the discussions on this feature
when this was introduced.
https://lwn.net/Articles/572765/
https://lwn.net/Articles/582200/

Cleaned-up the arch_read_xxx and arch_write_xxx definitions in spinlock_64.h.
These routines are replaced by the functions in include/asm-generic/qrwlock.h
Signed-off-by: NBabu Moger <babu.moger@oracle.com>
Reviewed-by: NHåkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: NJane Chu <jane.chu@oracle.com>
Reviewed-by: NShannon Nelson <shannon.nelson@oracle.com>
Reviewed-by: NVijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>