lin_gadget: use common linux/compat.h

Merge our duplicate definitions with the common header.

Also fix drivers/usb/gadget/s3c_udc_otg_xfer_dma.c to
use min() instead of min_t() since we remove the latter
from compat.h.

Additionally use memalign() directly as the lin_gadget
specific kmalloc() macro is removed from lin_gadget_compat.h
by this patch.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Lukasz Majewski <l.majewski@samsung.com>