usb: gadget: storage_common: add methods to show/store 'cdrom' and 'removable'

This will be required by configfs integration.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2 files changed