usb: composite gadget: set vbus_draw current limitation during suspend

This patch modifies the composite gadget to set vbus_draw current limitation
during suspend state. This current limitation in suspend state shouldn't be
more than 2.5mA

Signed-off-by: Hao Wu <hao.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>