Rename remaining linux32 symbols such as linux_sysent[] and
linux_syscallnames[] from linux_* to linux32_* to avoid conflicts with
linux64.ko. While here, add support for linux64 binaries to systrace.

• Update NOPROTO entries in amd64/linux/syscalls.master to match the main table to fix systrace build.
• Add a special case for union l_semun arguments to the systrace generation.
• The systrace_linux32 module now only builds the systrace_linux32.ko. module on amd64.
• Add a new systrace_linux module that builds on both i386 and amd64. For i386 it builds the existing systrace_linux.ko. For amd64 it builds a systrace_linux.ko for 64-bit binaries.

Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D3954