feat: moved libk stuff to libk folder

kernel/libk/syscall.c

@@ -0,0 +1,22 @@
+//
+// Created by rick on 22-02-21.
+//
+
+#include "syscall.h"
+#include <types.h>
+#include <attributes.h>
+
+void syscall1(uint32_t arg1) {
+    __asm__("int $0x80"
+    :
+    : "a"(arg1));
+}
+
+void syscall_yield_job() {
+    syscall1(SYSCALL_YIELD_JOB);
+}
+
+void noreturn syscall_start_scheduler() {
+    syscall1(SYSCALL_START_SCHEDULER);
+    while (1) { __asm__("hlt"); };
+}