usb: gadget: Fix disabling L1 LPM capability on SS devices connected as HS

Commit 628fd947 ("usb: gadget: Disable L1 LPM capability") sets
the USB version of Superspeed devices connected at High Speed devices
as 0x0200.
Consider the below case:
1. Connect HS cable - USB type is 0x0200
2. Disconnect HS cable and connect SS cable - USB type is 0x0300
3. Disconnect SS cable and again connect HS cable - USB type is 0x0300
So for Superspeed devices connected at High Speed incorrect USB type
is being set.
Fix this by adding a simple else check and explicitly setting it to 0x0200.

Change-Id: I5746049870973bcdbe38ccfda56fec5c8e8f0f13
Signed-off-by: Azhar Shaikh <azhars@codeaurora.org>