feat: added missing lapic code

kernel/cpu/lapic.c

@@ -0,0 +1,30 @@
+//
+// Created by rick on 23-08-21.
+//
+
+#include <myke/cpu/lapic.h>
+
+void *lapic = NULL;
+
+void lapic_set_addr(uint32_t addr) {
+    lapic = (void *) addr;
+}
+
+void lapic_write(uint32_t offset, uint32_t value) {
+    *(volatile uint32_t *) ((uintptr_t) lapic + offset) = value;
+}
+
+uint32_t lapic_read(uint32_t offset) {
+    if (lapic == NULL) {
+        return UINT32_MAX;
+    }
+    return *(volatile uint32_t *) ((uintptr_t) lapic + offset);
+}
+
+uint32_t lapic_get_id() {
+    return lapic_read(LAPIC_REG_ID);
+}
+
+uint32_t lapic_get_version() {
+    return lapic_read(LAPIC_REG_VERSION);
+}