powerpc/p3041: Add various p3041 related defines

There are various locations that we have chip specific info:

* Makefile for which ddr code to build
* Added p3041 to cpu_type_list and SVR list
* Added number of LAWs for p3041
* Set CONFIG_MAX_CPUS to 4 for p3041

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>