usb: gadget: fsl_qe_udc: fix implicit-fallthrough warnings

Quieten implicit-fallthrough warnings in fsl_qe_udc.c:

../drivers/usb/gadget/udc/fsl_qe_udc.c: In function 'qe_ep_init':
../drivers/usb/gadget/udc/fsl_qe_udc.c:542:37: warning: this statement may fall through [-Wimplicit-fallthrough=]
  542 |    if ((max == 128) || (max == 256) || (max == 512))
../drivers/usb/gadget/udc/fsl_qe_udc.c:563:8: warning: this statement may fall through [-Wimplicit-fallthrough=]
  563 |     if (max <= 1024)
../drivers/usb/gadget/udc/fsl_qe_udc.c:566:8: warning: this statement may fall through [-Wimplicit-fallthrough=]
  566 |     if (max <= 64)
../drivers/usb/gadget/udc/fsl_qe_udc.c:580:8: warning: this statement may fall through [-Wimplicit-fallthrough=]
  580 |     if (max <= 1024)
../drivers/usb/gadget/udc/fsl_qe_udc.c:596:5: warning: this statement may fall through [-Wimplicit-fallthrough=]
  596 |     switch (max) {

This basically just documents what is currently being done.
If any of them need to do something else, just say so or
even make the change.

Cc: Li Yang <leoyang.li@nxp.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210428040855.25907-1-rdunlap@infradead.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/fsl_qe_udc.c

@@ -541,6 +541,7 @@ static int qe_ep_init(struct qe_udc *udc,
 			case USB_SPEED_HIGH:
 			if ((max == 128) || (max == 256) || (max == 512))
 				break;
+			fallthrough;
 			default:
 				switch (max) {
 				case 4:
@@ -562,9 +563,11 @@ static int qe_ep_init(struct qe_udc *udc,
 			case USB_SPEED_HIGH:
 				if (max <= 1024)
 					break;
+				fallthrough;
 			case USB_SPEED_FULL:
 				if (max <= 64)
 					break;
+				fallthrough;
 			default:
 				if (max <= 8)
 					break;
@@ -579,6 +582,7 @@ static int qe_ep_init(struct qe_udc *udc,
 			case USB_SPEED_HIGH:
 				if (max <= 1024)
 					break;
+				fallthrough;
 			case USB_SPEED_FULL:
 				if (max <= 1023)
 					break;
@@ -605,6 +609,7 @@ static int qe_ep_init(struct qe_udc *udc,
 				default:
 					goto en_done;
 				}
+				fallthrough;
 			case USB_SPEED_LOW:
 				switch (max) {
 				case 1: