A lot of changes on acpi driver code.

A lot of changes on acpi driver code.
 - The "Osd*" stuff went away from acpi driver code, use the bus_space
   functions directly instead.
 - Fix minor english bugs.
   acpi_registers_input  -> acpi_register_input
   acpi_registers_output -> acpi_register_output
 - Remove all magic numbers for the sleeping states.  We now have
   #defines for these.
 - NULL is treated the same as the return from aml_get_rootname in
   aml_find_from_namespace().

Suggested by:	msmith

Thanks mike!