[PATCH] powerpc: DABR exceptions should report the address not the PC

When taking a DABR exception we were reporting the PC. It makes more
sense to report the address that caused the exception, and the gdb guys
would like it that way.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>