ARM: fix LTO for rockchip and samsung

When building with LTO, the compiler complains about type mismatch of
function usb_gadget_handle_interrupts(). This function is defined
without parameters in files
  arch/arm/mach-rockchip/board.c
  board/samsung/common/exynos5-dt.c
but it should have one parameter, int index.

Fix this.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>