usb: gadget: u_smd: Initiate remote_wakeup only if enabled by host

Driver currently tries to initiate remote-wakeup without checking
whether host enabled it or not. This can result in device to exit
low power mode to initiate remote-wakeup. However host may not
resume bus, resulting in device staying out of low power state
waiting for host to resume bus which increases device power
consumption.

Change-Id: I2aa67cf88f6bc14757856dbd5c48c74b9a2a2b56
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>