usb: gadget: udc: renesas_usb3: Fix usb_gadget_giveback_request() calling

commit aca5b9ebd096039657417c321a9252c696b359c2 upstream.

According to the gadget.h, a "complete" function will always be called
with interrupts disabled. However, sometimes usb3_request_done() function
is called with interrupts enabled. So, this function should be held
by spin_lock_irqsave() to disable interruption. Also, this driver has
to call spin_unlock() to avoid spinlock recursion by this driver before
calling usb_gadget_giveback_request().

Reported-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Tested-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Fixes: 746bfe63 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>