usb: cdns3: fix iso transfer error when mult is not zero

ISO basic transfer is
	ITP(SOF) Package_0 Package_1 ... Package_n

CDNS3 DMA start dma transfer from memmory to internal FIFO when get SOF,
controller will transfer data to usb bus from internal FIFO when get IN
token.

According USB spec defination:
	Maximum number of packets = (bMaxBurst + 1) * (Mult + 1)

Internal memory should be the same as (bMaxBurst + 1) * (Mult + 1). DMA
don't fetch data advance when ISO transfer, so only reserve
(bMaxBurst + 1) * (Mult + 1) internal memory for ISO transfer.

Need save Mult and bMaxBurst information and set it into EP_CFG register,
otherwise only 1 package is sent by controller, other package will be
lost.

Cc:  <stable@vger.kernel.org>
Fixes: 7733f6c3

 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231224153816.1664687-3-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>