powerpc/booke: Fix definitions for dbcr[1-2] and dbsr registers

This takes values from the PowerPC ISA BookIII-E specifications that are
for DBCR0. Many of these values are different from those currently
specified, which are for the ppc405. Also added some bookE definitions
for DBCR1 & DBCR2.

[ galak@kernel.crashing.org: Added aliases to 40x DBCR0 to match Book-E,
  Added enhanced debug DBCR0/DBSR _CIRPT and _CRET defines and DBSR
  IRPT and RET. ]

Signed-off-by: Jerone Young <jyoung5@us.ibm.com>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>