remove unnecessary <linux/hdreg.h> includes

Following files don't need <linux/hdreg.h> at all:

- arch/mips/jazz/setup.c
- arch/sh/boards/mach-systemh/irq.c
- drivers/macintosh/mediabay.c
- drivers/scsi/hptiop.c
- drivers/usb/storage/freecom.c
- arch/powerpc/include/asm/ide.h
- init/main.c

Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>