arm/cpu: Replace license and copyright boilerplate by SPDX identfiers ...

This adapts all files that were identifed by licensecheck
(https://salsa.debian.org/build-common-team/licensecheck.git) as
licensed under the GPL.

While touching these files also do some minor comment reformatting to
get some uniform layout.

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

ARM: move linker variable declarations to sections.h ...

We collected most linker variable declarations in asm/sections.h, so
move __exceptions_start/__exceptions_stop there aswell.

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

ARM: Fix exception table setup in MMU-less mode ...

Add code necessary for correct initialization of exception vector
table when MMU is disabled.

Note: Only ARMv7 support is implemented

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>