habanalabs: Switch to using the new API kobj_to_dev()

fixed the following coccicheck:
./drivers/misc/habanalabs/common/sysfs.c:347:60-61: WARNING opportunity
for kobj_to_dev()

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>