greybus: es2: use a single bulk ep pair for all greybus data

This matches a corresponding firmware change to declare a single
BULK EP pair for all greybus traffic and 1 BULK IN ep for ARPC.

Thus, avoiding URB submittions for all the other unused BULK IN
endpoints on the HOST side that took considerable amount
of bus time.

Testing Done:
Tested with modified AP<->APB1 loopback test and also with GPBridge
modules to ensure there are no regressions
Signed-off-by: Sandeep Patil <sspatil@google.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/es2.c

@@ -47,7 +47,7 @@ MODULE_DEVICE_TABLE(usb, id_table);
 #define APB1_LOG_SIZE		SZ_16K
 
 /* Number of bulk in and bulk out couple */
-#define NUM_BULKS		7
+#define NUM_BULKS		1
 
 /* Expected number of bulk out endpoints */
 #define NUM_BULKS_OUT		NUM_BULKS