[MIPS] IP32 Fix and complete IP32 parport definitions

    
Fix, complete, and indent IP32 parport definitions.
Definition were wrong for CTXINUSE and DMACTIVE (1-bit shift).
Add macros DATA_BOUND, DATALEN_SHIFT, and CTRSHIFT.
    
Signed-off-by: Arnaud Giersch <arnaud.giersch@free.fr>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>