85xx: Reworked initial processor init

85xx: Reworked initial processor init

Reworked the initial processor initialzation sequence:
* introduced cpu_early_init_f that is run in address space 1 (AS=1)
* Moved TLB/LAW and CCSR init into cpu_early_init_f()
* Reworked initial asm code to do most of the core init before TLBs

The main reasons for these changes are to allow handling of 36-bit phys
addresses in the future and some of the issues that will exist when we
do that.

There are a few caveats on what can be initialized via the LAW and TLB
static tables:
* TLB entry 14/15 can't be initialized via the TLB table
* any LAW that covers the implicit boot window (4G-8M to 4G) must map to
  the code that is currently executing.

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