Copy syscall.tbl and syscallhdr.sh from linux/arch/parisc/kernel/syscalls v5.5
Update syscallhdr.sh to generate QEMU syscall_nr.h

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200310103403.3284090-4-laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>