This patch adds the controller helper codes to hda-core library.
The I/O access ops are added to the bus ops.  The CORB/RIRB, the basic
attributes like irq# and iomap address, some locks and the list of
streams are added to the bus object, together with the stream object
and its helpers.

Currently the codes are just copied from the legacy driver, so you can
find duplicated codes in both directories.  Only constants are removed
from the original hda_controller.h.  More integration work will follow
in the later patches.
Signed-off-by: Takashi Iwai <tiwai@suse.de>