usb: dwc3: drop CONFIG_USB_DWC3_DEBUG

now that we have no users of dev_dbg() in dwc3,
we can safely remove CONFIG_USB_DWC3_DEBUG.

If dev_dbg() is ever strictly necessary - and I
don't see why it would, considering we want to
rely on tracepoints for debug - we will depend
on DYNAMIC_PRINTK to enable such messages.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/Kconfig

@@ -104,11 +104,4 @@ config USB_DWC3_QCOM
 	  Recent Qualcomm SoCs ship with one DesignWare Core USB3 IP inside,
 	  say 'Y' or 'M' if you have one such device.
 
-comment "Debugging features"
-
-config USB_DWC3_DEBUG
-	bool "Enable Debugging Messages"
-	help
-	  Say Y here to enable debugging messages on DWC3 Driver.
-
 endif

drivers/usb/dwc3/Makefile

 # define_trace.h needs to know how to find our header
 CFLAGS_trace.o				:= -I$(src)
 
-ccflags-$(CONFIG_USB_DWC3_DEBUG)	:= -DDEBUG
-
 obj-$(CONFIG_USB_DWC3)			+= dwc3.o
 
 dwc3-y					:= core.o debug.o trace.o