csky: Fixup compile error

: error: C++ style comments are not allowed in ISO C90
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
^
error: (this will be reported only once per input file)

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

csky: Fixup init_fpu compile warning with __init

WARNING: vmlinux.o(.text+0x2366): Section mismatch in reference from the
function csky_start_secondary() to the function .init.text:init_fpu()

The function csky_start_secondary() references
the function __init init_fpu().
This is often because csky_start_secondary lacks a __init
annotation or the annotation of init_fpu is wrong.

Reported-by: Lu Chongzhi <chongzhi.lcz@alibaba-inc.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

csky: Process management and Signal

This patch adds files related to task_switch, sigcontext, signal,
fpu context switch.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Eric W. Biederman <ebiederm@xmission.com>