usb: host: oxu210hp: remove unused struct 'ehci_dbg_port'

'ehci_dbg_port' is unused in oxu210hp-hcd.c since it's original
commit b92a78e5 ("usb host: Oxford OXU210HP HCD driver.")
when it was in a separate header.

Remove it.

Note, that this structure, and some others in the driver
are mostly clones of include/linux/usb/ehci_def.h.
Someone with the hardware to be able to test it might
be able to remove a lot more structs as well and just
use that header.
Signed-off-by: "Dr. David Alan Gilbert" <linux@treblig.org>
Link: https://lore.kernel.org/r/20240529210002.106369-1-linux@treblig.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/oxu210hp-hcd.c

@@ -196,31 +196,6 @@ struct ehci_regs {
 #define PORT_RWC_BITS   (PORT_CSC | PORT_PEC | PORT_OCC)
 } __packed;
 
-/* Appendix C, Debug port ... intended for use with special "debug devices"
- * that can help if there's no serial console.  (nonstandard enumeration.)
- */
-struct ehci_dbg_port {
-	u32	control;
-#define DBGP_OWNER	(1<<30)
-#define DBGP_ENABLED	(1<<28)
-#define DBGP_DONE	(1<<16)
-#define DBGP_INUSE	(1<<10)
-#define DBGP_ERRCODE(x)	(((x)>>7)&0x07)
-#	define DBGP_ERR_BAD	1
-#	define DBGP_ERR_SIGNAL	2
-#define DBGP_ERROR	(1<<6)
-#define DBGP_GO		(1<<5)
-#define DBGP_OUT	(1<<4)
-#define DBGP_LEN(x)	(((x)>>0)&0x0f)
-	u32	pids;
-#define DBGP_PID_GET(x)		(((x)>>16)&0xff)
-#define DBGP_PID_SET(data, tok)	(((data)<<8)|(tok))
-	u32	data03;
-	u32	data47;
-	u32	address;
-#define DBGP_EPADDR(dev, ep)	(((dev)<<8)|(ep))
-} __packed;
-
 #define	QTD_NEXT(dma)	cpu_to_le32((u32)dma)
 
 /*