USB: cdc-acm - Add IGNORE_DEVICE quirk

Extracted from commit 16142655 ("USB: cdc-acm - blacklist IMS PCU
device").
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/usb/class/cdc-acm.c

@@ -916,6 +916,10 @@ static int acm_probe(struct usb_interface *intf,
 
 	/* normal quirks */
 	quirks = (unsigned long)id->driver_info;
+
+	if (quirks == IGNORE_DEVICE)
+		return -ENODEV;
+
 	num_rx_buf = (quirks == SINGLE_RX_URB) ? 1 : ACM_NR;
 
 	/* handle quirks deadly to normal probing*/

drivers/usb/class/cdc-acm.h

@@ -127,4 +127,5 @@ struct acm {
 #define NO_CAP_LINE			4
 #define NOT_A_MODEM			8
 #define NO_DATA_INTERFACE		16
+#define IGNORE_DEVICE			32
 #define CLEAR_HALT_CONDITIONS		BIT(7)