usb: gadget: uvc: Correct documentation formatting

The documentation table added in a36afe78 ("usb: gadget: uvc: Add
new enable_interrupt_ep attribute") was incorrect, resulting in a new
warning when compiling the documentation.

Correct the formatting to resolve the warning.

Fixes: a36afe78

 ("usb: gadget: uvc: Add new enable_interrupt_ep attribute")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206151131.863960-1-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>