usb: gadget: composite: remove redundant bcdUSB setting in legacy

Since composite now overwrites bcdUSB for any gadget, remove
setting it in legacy gadgets. All legacy gadgets set 0x0200, the
same as the value additionally set by composite, so there is no
behaviour change.

Signed-off-by: Igor Kotrasinski <i.kotrasinsk@samsung.com>

Rebase onto current balbi/next

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>