floppy: introduce new functions fdc_inb() and fdc_outb()

These two functions replace fd_inb() and fd_outb() in that they take
the FDC in argument. This will ease the separation of the base address
and the port everywhere the code is used.

Link: https://lore.kernel.org/r/20200301195555.11154-5-w@1wt.eu
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>