Declare reset_cpu() in include/common.h instead locally

ARM memory layout fixes: the abort-stack is now set up in the
correct RAM area, and the BSS is zeroed out as it should be.

Furthermore, the magic variables 'armboot_end' and 'armboot_end_data'
of the linker scripts are replaced by '__bss_start' and '_end',
resp., which is a further step to eliminate unnecessary differences
between the implementation of the CPU architectures.

  Move most of the timer interrupt related PPC code to ppc_lib/interrupts.c

* Patch by Anders Larsen, 17 Sep 2003:
  Bring ARM memory layout in sync with the documentation:
  stack and malloc-heap are now located _below_ the U-Boot code

  fix TI Innovator/OMAP1510 pin configs

* Patches by Kshitij, 18 Aug 2003
  - add support for arm926ejs cpu core
  - add support for TI OMAP 1610 Innovator Board

- added support for arm925t cpu core
- added support for TI OMAP 1510 Innovator Board