mei: rename interface to hw-me

Rename hw-me.h to hw-me-regs.h as this file
contains only register definitions.
Files hw-me.[ch] now contains ME hw dependant
functionality

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>