translate-all.c: Multi-level page maps.

This brings translate-all.c to a state much closer to upstream.
The major difference is the implementation of multi-level page
tables (for PageDesc and PhysPageDesc entries). This is a preliminary
requirement to handle 64-bit address spaces properly.

+ Move cpu_interrupt() from exec.c to translate-all.c

Change-Id: I12f17cc92faa51cf6eb9ceba2be4b29817eed5fe
9 files changed