treewide: remove references to CREDITS ...

The CREDITS file was removed from barebox in 2015 by commit 6570288f2d97
("Remove the CREDITS file"). Remove references to it from several files.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add warning above get_ram_size ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Treewide: remove address of the Free Software Foundation ...

The FSF address has changed in the past. Instead of updating it
each time the address changes, just drop it completely treewide.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common/memsize.c: add missing include ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

[sandbox] add propper sandbox detection ...

This patch adds a __SANDBOX__ define to identify compiling for the
sandbox.
When building for sandbox, don't use sync() workaround.

Fixes this error for sandbox on PPC:

CC      common/memsize.o
common/memsize.c:30:38: error: asm/io.h: No such file or directory
common/memsize.c: In function 'get_ram_size':
common/memsize.c:51: warning: implicit declaration of function 'sync'

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Sequential accesses to non-existent memory must be synchronized, ...

at least on G2 cores.

This fixes get_ram_size() problems on MPC5200 Rev. B boards.

Add a common get_ram_size() function and modify the the ...

board-specific files to invoke that common implementation.