sim: m32r: namespace Linux syscall table

sim: m32r: namespace Linux syscall table

The use of __NR_ defines in here conflicts a lot with the standard
host syscalls, sometimes leading to build errors (when the numbers
happen to be the same we get duplicate case handlers), and other
times leading to misbehavior (where the m32r syscall # is not what
is actually checked).

Namespace these using the standard that we already use: change the
__NR_ to TARGET_LINUX_SYS_ with a simple `sed`.

Also add a few missing includes so the code at least compiles.