Extend USB gadget configuration for usb debug mode.

Extend USB gadget configuration for usb debug mode.

In MCD user mode binary, sdb is disabled and mtp mode is only enabled.
When you enable debug mode(on Setting menu), both sdb is enabled.
As a result, sdb and mtp are enabled.
But, there were no configuration of SDB + MTP mode.

Device log at this situation.
//////////////////////////////////////////////////////////////////////
01-15 22:25:31.787 I/DEVICED (P 2608, T 2608): usb-debug.c: usb_debug_changed(64) > USB debug ON.
01-15 22:25:31.788 I/DEVICED (P 2608, T 2608): usb-debug.c: usb_debug_mode_changed(81) > Previous mode(1).
01-15 22:25:31.788 I/DEVICED (P 2608, T 2608): usb-debug.c: usb_debug_mode_changed(88) > New mode(5).
01-15 22:25:31.789 E/DEVICED (P 2608, T 2608): usb.c: usb_change_gadget(244) > Unable to translate id into gadget: -22
01-15 22:25:31.789 E/DEVICED (P 2608, T 2608): usb.c: usb_change_mode(332) > Failed to change gadget: -22
///////////////////////////////////////////////////////////////////////

Change-Id: Ic3f5420603b8ef02411ed429540542710415685b