arch,sim: Drop the syscall number from the syscall func signature.

This value is almost never used, and is now part of the SyscallDesc.

Change-Id: Ia4ffc19774bb2eac8f29134e3765c06a264407b6
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24118
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/sim/process.cc

@@ -428,7 +428,7 @@ Process::doSyscall(int64_t callnum, ThreadContext *tc, Fault *fault)
     if (desc == nullptr)
         fatal("Syscall %d out of range", callnum);
 
-    desc->doSyscall(callnum, tc, fault);
+    desc->doSyscall(tc, fault);
 }
 
 EmulatedDriver *