powerpc/uapi: Fix sigcontext definition to use user_pt_regs

My recent patch to split pt_regs between user and kernel missed
the usage in struct sigcontext.

Because this is a user visible struct it should be using the user
visible definition, which when we're building for the kernel is called
struct user_pt_regs.

As far as I can see this hasn't actually caused a bug (yet), because
we don't use the sizeof() the sigcontext->regs anywhere. But we should
still fix it to avoid confusion and future bugs.

Fixes: 002af9391bfb ("powerpc: Split user/kernel definitions of struct pt_regs")
Reported-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

License cleanup: add SPDX license identifier to uapi header files with a license

Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.

Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.

GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:

NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".

This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.

Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)

SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

powerpc/signal: Fix confusing header documentation in sigcontext.h

Commit ce48b2100785 "powerpc: Add VSX context save/restore, ptrace and
signal support" expanded the 'vmx_reserve' array element to contain 101
double words, but the comment block above was not updated.

Also reorder the constants in the array size declaration to reflect the
logic mentioned in the comment block above. This change helps in
explaining how the HW registers are represented in the array. But no
functional change.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
[mpe: Reworded change log and added whitespace around +'s]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

UAPI: (Scripted) Disintegrate arch/powerpc/include/asm

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>