This patch adds oprofile support for the 7450 and all its multitudinous
derivatives.

* Added 7450 (and derivatives) support for oprofile
* Changed e500 cputable to have oprofile model and cpu_type fields
* Added support for classic 32-bit performance monitor interrupt
* Cleaned up common powerpc oprofile code to be as common as possible
* Cleaned up oprofile_impl.h to reflect 32 bit classic code
* Added 32-bit MMCRx bitfield definitions and SPR numbers

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>