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>

Fix style issues primarily in 85xx and 83xx boards.
- C++ comments
- Trailing white space
- Indentation not by TAB
- Excessive amount of empty lines
- Trailing empty lines

* Patch by Jon Loeliger, 2005-05-05
Implemented support for MPC8548CDS board.
Added DDR II support based on SPD values for MPC85xx boards.
This roll-up patch also includes bugfies for the previously
published patches:
DDRII CPO, pre eTSEC, 8548 LBIU, Andy's TSEC, eTSEC 3&4 I/O

* Patch by Rune Torgersen, 13 Feb 2003:
Add support for Motorola MPC8266ADS board

* Patch by Kyle Harris, 19 Feb 2003:
patches for the Intel lubbock board:
memsetup.S - general cleanup (based on Robert's csb226 code)
flash.c - overhaul, actually works now
lubbock.c - fix init funcs to return proper value

* Patch by Kenneth Johansson, 26 Feb 2003:
- Fixed off by one in RFTA calculation.
- No need to abort when LDF is lower than we can program it's only
minimum timing so clamp it to what we can do.
- Takes function pointer to function for reading the spd_nvram. Usefull
for faking data or hardcode a module without the nvram.
- fix other user for above change
- fix some comments.

* Patches by Brian Waite, 26 Feb 2003:
- fix port for evb64260 board
- fix PCI for evb64260 board
- fix PCI scan

* Patch by Reinhard Meyer, 1 Mar 2003:
Add support for EMK TOP860 Module

* Patch by Yuli Barcohen, 02 Mar 2003:
Add SPD EEPROM support for MPC8260ADS board