usb: otg-fsm: Prevent build warning "VDBG" redefined

If usb/otg-fsm.h and usb/composite.h are included together
then it results in the build warning [1].

Prevent that by defining VDBG locally.

Also get rid of MPC_LOC which doesn't seem to be used
by anyone.

[1] - warning fixed by this patch:

In file included from drivers/usb/dwc3/core.h:33,
   from drivers/usb/dwc3/ep0.c:33:
   include/linux/usb/otg-fsm.h:30:1: warning: "VDBG" redefined
   In file included from drivers/usb/dwc3/ep0.c:31:
   include/linux/usb/composite.h:615:1: warning: this is the location
   of the previous definition

Signed-off-by: Roger Quadros <rogerq@ti.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Acked-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>