habanalabs: clean MMU headers definitions

During the MMU development the MMU header files were left with unclean
definitions:

- MMU "version specific" definitions that were left in the mmu_general
  file
- unused definitions

This patch attempts, where possible, to keep definitions that can serve
multiple MMU versions (but that are not tightly bound with specific MMU
arch) in the mmu_general header file (e.g. different definitions for
number of HOPs).

Otherwise, move MMU version specific definitions (e.g. HOPs masks and
shifts) to the specific MMU version file.

Signed-off-by: Ohad Sharabi <osharabi@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>