CRIS: Wire up missing syscalls

The related warnings:

    CALL    scripts/checksyscalls.sh
  <stdin>:1229:2: warning: #warning syscall sched_setattr not implemented [-Wcpp]
  <stdin>:1232:2: warning: #warning syscall sched_getattr not implemented [-Wcpp]
  <stdin>:1235:2: warning: #warning syscall renameat2 not implemented [-Wcpp]
  <stdin>:1238:2: warning: #warning syscall seccomp not implemented [-Wcpp]
  <stdin>:1241:2: warning: #warning syscall getrandom not implemented [-Wcpp]
  <stdin>:1244:2: warning: #warning syscall memfd_create not implemented [-Wcpp]
  <stdin>:1247:2: warning: #warning syscall bpf not implemented [-Wcpp]
  <stdin>:1250:2: warning: #warning syscall execveat not implemented [-Wcpp]

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Jesper Nilsson <jespern@axis.com>