libbpf: Clean up now not needed __PT_PARM{1-6}_SYSCALL_REG defaults

Each architecture supports at least 6 syscall argument registers, so now
that specs for each architecture is defined in bpf_tracing.h, remove
unnecessary macro overrides, which previously were required to keep
existing BPF_KSYSCALL() uses compiling and working.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230120200914.3008030-26-andrii@kernel.org

tools/lib/bpf/bpf_tracing.h

@@ -476,24 +476,6 @@ struct pt_regs;
  *
  * See syscall(2) manpage for succinct table with information on each arch.
  */
-#ifndef __PT_PARM1_SYSCALL_REG
-#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
-#endif
-#ifndef __PT_PARM2_SYSCALL_REG
-#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
-#endif
-#ifndef __PT_PARM3_SYSCALL_REG
-#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
-#endif
-#ifndef __PT_PARM4_SYSCALL_REG
-#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
-#endif
-#ifndef __PT_PARM5_SYSCALL_REG
-#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
-#endif
-#ifndef __PT_PARM6_SYSCALL_REG
-#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
-#endif
 #ifndef __PT_PARM7_SYSCALL_REG
 #define __PT_PARM7_SYSCALL_REG __unsupported__
 #endif