usb: cdns3: allocate TX FIFO size according to composite EP number

[ Upstream commit dce49449

 ]

Some devices have USB compositions which may require multiple endpoints.
To get better performance, need bigger CDNS3_EP_BUF_SIZE.

But bigger CDNS3_EP_BUF_SIZE may exceed total hardware FIFO size when
multiple endpoints.

By introducing the check_config() callback, calculate CDNS3_EP_BUF_SIZE.

Move CDNS3_EP_BUF_SIZE into cnds3_device: ep_buf_size
Combine CDNS3_EP_ISO_SS_BURST and CDNS3_EP_ISO_HS_MULT into
cnds3_device:ep_iso_burst

Using a simple algorithm to calculate ep_buf_size.
ep_buf_size = ep_iso_burst = (onchip_buffers - 2k) / (number of IN EP +
1).

Test at 8qxp:

	Gadget			ep_buf_size

	RNDIS:				5
	RNDIS+ACM:			3
	Mass Storage + NCM + ACM	2

Previous CDNS3_EP_BUF_SIZE is 4, RNDIS + ACM will be failure because
exceed FIFO memory.

Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20220509164055.1815081-1-Frank.Li@nxp.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: dbe678f6

 ("usb: cdns3: fix NCM gadget RX speed 20x slow than expection at iMX8QM")
Signed-off-by: Sasha Levin <sashal@kernel.org>