SPDX: Convert all of our single license tags to Linux Kernel style

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from. So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry. Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents. There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>

Add GPL-2.0+ SPDX-License-Identifier to source files

Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>

Code cleanup

Various USB related patches
- Add support for mpc8xx USB device.
- Add support for Common Device Class - Abstract Control Model USB console.
- Add support for flow control in USB slave devices.
- Add support for switching between gserial and cdc_acm using environment.
- Minor changes to usbdcore_omap1510.c usbdcore_omap1510.h
- Update usbcore slightly to ease host enumeration.
- Fix non-portable endian problems in usbdcore and usbdcore_ep0.
- Add AdderUSB_config as a defconfig to enable usage of the USB console
by default with the Adder87x U-Boot port.
Patches by Bryan O'Donoghue <bodonoghue@codehermit.ie>, 29 May 2006