lkl: follow up fixes after v5.3 merge (ptrace)

Fixes: 201766a ("ptrace: add PTRACE_GET_SYSCALL_INFO request")

Signed-off-by: Hajime Tazaki <thehajime@gmail.com>

Author: thehajime

arch/lkl/include/asm/Kbuild

@@ -67,6 +67,7 @@ generic-y += statfs.h
 generic-y += string.h
 generic-y += swab.h
 generic-y += switch_to.h
+generic-y += syscall.h
 generic-y += termbits.h
 generic-y += termios.h
 generic-y += time.h