usb: chipidea: add tx/rx burst size configuration interface

The user can adjust it through dts or platform data

Signed-off-by: Peter Chen <peter.chen@freescale.com>
diff --git a/drivers/usb/chipidea/bits.h b/drivers/usb/chipidea/bits.h
index 462ad02..e462f55 100644
--- a/drivers/usb/chipidea/bits.h
+++ b/drivers/usb/chipidea/bits.h
@@ -61,6 +61,10 @@
 /* Set non-zero value for internal TT Hub address representation */
 #define TTCTRL_TTHA		(0x7fUL << 24)
 
+/* BURSTSIZE */
+#define RX_BURST_MASK		0xff
+#define TX_BURST_MASK		0xff00
+
 /* PORTSC */
 #define PORTSC_CCS            BIT(0)
 #define PORTSC_CSC            BIT(1)