usb: renesas-xhci: Add the renesas xhci driver

usb: renesas-xhci: Add the renesas xhci driver

This add a new driver for renesas xhci which is basically a firmware
loader for uPD720201 and uPD720202 w/o ROM. The xhci-pci driver will
invoke this driver for loading/unloading on relevant devices.

This patch adds a firmware loader for the uPD720201K8-711-BAC-A
and uPD720202K8-711-BAA-A variant. Both of these chips are listed
in Renesas' R19UH0078EJ0500 Rev.5.00 "User's Manual: Hardware" as
devices which need the firmware loader on page 2 in order to
work as they "do not support the External ROM".

The "Firmware Download Sequence" is describe in chapter
"7.1 FW Download Interface" R19UH0078EJ0500 Rev.5.00 page 131.

The firmware "K2013080.mem" is available from a USB3.0 Host to
PCIe Adapter (PP2U-E card) "Firmware download" archive. An
alternative version can be sourced from Netgear's WNDR4700 GPL
archives.

The release notes of the PP2U-E's "Firmware Download" ver 2.0.1.3
(2012-06-15) state that the firmware is for the following devices:
 - uPD720201 ES 2.0 sample whose revision ID is 2.
 - uPD720201 ES 2.1 sample & CS sample & Mass product, ID is 3.
 - uPD720202 ES 2.0 sample & CS sample & Mass product, ID is 2.

[vkoul: fixed comments:
	used macros for timeout count and delay
	removed renesas_fw_alive_check
	cleaned renesas_fw_callback
	removed recursion for renesas_fw_download
	add register defines and field names
	move to a separate file
	make fw loader as sync probe so that we execute in probe and
        prevent race
	make xhci-pci-renesas a seprate module]

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20200514122039.300417-3-vkoul@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>