linux-user, mips64: add syscall table generation support

Copy syscall_n32.tbl, syscall_n64.tbl and syscallhdr.sh from
linux/arch/parisc/kernel/syscalls v5.5
Update syscallhdr.sh to generate QEMU syscall_nr.h

Move the offsets (6000 for n32 and 5000 for n64) from the file to
the Makefile.objs to be passed to syscallhdr.sh

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20200310103403.3284090-18-laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
7 files changed