linux-user: Add support for FDFMT<BEG|TRK|END> ioctls

linux-user: Add support for FDFMT<BEG|TRK|END> ioctls

FDFMTBEG, FDFMTTRK, and FDFMTEND ioctls provide means for controlling
formatting of a floppy drive.

FDFMTTRK's third agrument is a pointer to the structure:

struct format_descr {
    unsigned int device,head,track;
};

defined in Linux kernel header <linux/fd.h>.

Since all fields of the structure are of type 'unsigned int', there is
no need to define "target_format_descr".

FDFMTBEG and FDFMTEND ioctls do not use the third argument.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Message-Id: <1579214991-19602-9-git-send-email-aleksandar.markovic@rt-rk.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>