IDE: combine portio r/w functions

Mark, here's a quick sketch for you. There are two things I don't like, but didn't care enough to fix:

(1) Restricting nbytes to 2 or 4 means some extra boilerplate to quiet compilers who don't know it will only ever be 2 or 4
(2) the address value is all-but-ignored, it carries over from the portio signature and is useful primarily for tracing, but it's a little ugly/deceiving to take a parameter and not use it.

John Snow (2):
ide: generic ide_data_read
ide: generic ide_data_write

 hw/ide/core.c             | 185 +++++++++++++++++++++-------------------------
 hw/ide/trace-events       |   7 +-
 include/hw/ide/internal.h |   4 +-
 3 files changed, 89 insertions(+), 107 deletions(-)

2.9.5